According to realdictionary.com, "Safety-first as an accident-prevention slogan first used in Britain in 1873" and may have originated with the US railroads.

According to a Letter to the Editor of the New York Times on Sept. 28, 1915 from Arthur Williams, then President of the American Museum of Safety, the "first organized work in accident prevention in this country was done in 1900 through the Museum of Safety Section of the American Institute of Social Service" (Copyright, The New York Times).

OSHA was founded in 1970.

Building	Address to give 911 operator
	(These are not postal or delivery addresses!)
Machine Laboratory (Annex)	488 Pine Tree Road, Town of Ithaca
Newman Laboratory	153 Sciences Drive, City of Ithaca
Physical Sciences Building (PSB)	142 Sciences Drive, City of Ithaca
Wilson Synchrotron Lab & Ring, G-Line	161 Synchrotron Drive, Town of Ithaca
East Modular Unit (Computer Group, Elec Shop)	142 Synchrotron Drive, Town of Ithaca
Center Modular Unit (Stockroom, Exploration Station)	150 Synchrotron Drive, Town of Ithaca
West Modular Unit (CHESS Trailer)	177 Synchrotron Drive, Town of Ithaca

Link to Cornell Police

Link to CLASSE safety personnel & phone numbers

Link to Cornell Police List of Emergency & Counseling numbers

Emergency.	911 (Campus phone only)
	(607) 255-1111 (cell phone or pay phone)
Receptionist for Wilson Lab (ask to page)	(607) 255-4882
Receptionist for Newman Lab (ask to page)	(607) 255-4952
Cayuga Medical Center Emergency	(607) 274-4411
Cornell Police Non-emergency	(607) 255-1111
Cornell Environmental Health and Safety	(607) 255-8200
Gannett Health Center	(607) 255-5155
Poison Control Center	(1-) 800-222-1222; (1-) 800-252-5655
Suicide Prevention & Crisis Service	(607) 272-1616

Short Term Visitor Policy:

Short Term Visitor Safety Policy

This policy sets out safety-related responsibilities of CLASSE personnel hosting short term visitors, contractors, or vendors to the lab, and those of such visitors once they are here.

1. Applies for any Laboratory visit extending beyond one working day. It does NOT apply to those already trained and vetted as collaborators or CHESS users. It does not apply to Cornell staff from Facilities, EH&S, or C.I.T.
2. A CLASSE host should assist each visitor in completing a short online form, after arrival but prior to commencing observation or work. This form gathers identifying information and a confirmation of safety training provided. (Part of this form replaces the paper "CLASSE Guest Agreement", which is no longer required.) For contractors, vendors, Cornellians, or an external committee, the CLASSE host may choose to fill out the online form on behalf of the individual or group.
3. A stay of longer than 7 working days involving experimental, shop, or technical spaces or activities requires taking the CLASSE Safety Orientation (and perhaps other training) through arrangement with the Safety Director, preferably prior to arrival on site (clarification: taking the CLASSE Safety Orientation is not required for PSB visitors who do not frequently access laboratory or technical spaces during their stay).
4. A CLASSE host must accompany the visitor at all times when first entering laboratory, shop, or technical work areas. This host function may be shared among several individuals or passed from one to another, but the host(s) must be explicitly aware of their role and responsibilities.
5. The CLASSE host or contact should instruct the visitor prior to arrival to enter the building through a public reception area and not to enter laboratory or technical areas unescorted . At Wilson Laboratory visitors should check in at the second floor CHESS reception desk.
6. A CLASSE host must show the visitor two emergency exit routes from any likely work area, and summarize hazards and relevant procedures local to those areas. In Wilson Laboratory, if likely work areas include areas on the first or second floor, relevant entrances to controlled areas should be pointed out so they can be either avoided entirely or consciously crossed.
7. A visitor may only observe unless provided with task-specific training consistent with CLASSE policy on that task and location. Vendors and contractors may work on designated equipment if they are familiar with it or receive appropriate training.
8. A radiation badge should be issued if the individual is likely to enter controlled areas over the course of more than one working day, and used for the entirety of the visit; otherwise, a host may sign out a dosimeter and accompany the visitor while inside controlled areas. If work in controlled areas is estimated to exceed 8 hours, the visitor must satisfy one of
   • take an in-person training (contact the Safety Director or Safety Manager), or
   • take the online CLASSE General Radiation Safety Training through arrangement with the Safety Director, preferably prior to arriving on site.
   • if the work is deemed by a CHESS staff member to be CHESS-user-like, take the CHESS User online safety training
9. If work is to occur in the CESR tunnel, a CLASSE host should contact one of Facilities Engineer, Safety Director, or Safety Manager to arrange for specialized (online or in-person) training.
10. A visitor already briefed on this policy and safety information may be left alone in work areas not requiring additional training if a designated CLASSE host in the building (e.g. an operator) is aware of the visitor, and the visitor understands how to request immediate assistance (designated host) or summon emergency services (911, nearest pushbutton call boxes, fire alarm pulls). If there are imminent safety hazards involved in the visitor's activities, or such hazards are in close proximity, the visitor may not work alone.
11. Special considerations apply to any short term visitor under the age of 18. For such individuals, please consult at least one of: CLASSE Administrator, CLASSE Safety Director, CLASSE Safety Manager.

Hazardous Materials

Before you begin any task, consider possible safety hazards of materials involved. Obtain, read and understand the Material Safety Data Sheets (SDS) for any new materials you use, machine, or handle in any way. Binders containing the SDS for chemicals in use are kept in the administrative offices, with a second copy nearer to likely workspaces. Smaller sets are kept in the shop areas and outside the Newman Chem room for convenient access. Be sure to give copies of the SDS to anyone else who will work with the chemical or material. List any additional hazards such as flammable or pressurized gases, large quantities of solvents or other chemicals, lasers, or radioactive sources. Decide what precautions you should take. If there are possible hazards to you or others or if you are unfamiliar with a new material or process, before you begin, you and your supervisor must take your plans to the Safety Director for a review.

You may also consult the EHS SDS pages.

Sometimes the quickest way to the SDS that you need is a web search for " SDS". If you locate one that is not already on file in the nearest appropriate notebook, put it there, and notify the CLASSE Safety Director.

Equipment Hazards

Wilson and Newman Labs are full of machinery and equipment that keep the experiment running. Alertness and preparation are imperative in order to ensure that the equipment remains helpful rather than hazardous. If you work with or around large machinery, be sure you know how to use it and how to avoid its hazards.

• Forklifts: Forklifts operate on the experimental floors at Newman and Wilson Labs. Stay clear of their paths. You must not operate a forklift unless you have been trained according to OSHA standards (see Safety Training).
• Overhead cranes: Overhead cranes are used to move heavy materials. When cranes are in use, lights flash and bells ring to alert those in the area, but hard hats are still required. Stay clear of overhead loads. Cranes must be operated only by properly trained personnel.
• Consult the EHS Mobile Equipment page

Shop Safety

Before using any machine tool, you must first be given explicit authorization from the Machine Shop Supervisor for that particular shop or piece of equipment. You should make an appointment with the shop supervisor to have one-on-one training. Analyze each job before you begin and consider how you can protect yourself from injury. It is crucial that you pay attention to potential hazards.

The following safety tips apply to both the machine shops and the experimental areas.

• Consult the EHS Tool & Machine Safety pages.
• Eye Safety: You must wear safety glasses when you are in any of the machine shops. Grinding, cutting, and drilling generate particles of metal, wood, lead, and other substances that could cause eye injuries in the absence of appropriate eye protection. You can use the safety glasses located near the shop entrances, or you may obtain a personal set from the stockroom. Check with the business office at Wilson for information about prescription safety glasses.
• Foot Safety: When you regularly work in the experimental areas or shop spaces, you must wear footwear with a protective-toe to protect your feet from being crushed. You may obtain safety shoes and boots from the periodic shoe truck visits, or you may purchase them on your own and be reimbursed (up to a certain amount) through the Wilson business office. Check with your supervisor to see if your job requires that you wear safety shoes. In addition, no open-toed shoes are permitted in experimental or machine shops (e.g. L0, L0E, CESR tunnel, any room in use as a lab).
• Hand Safety: Keep the following tips in mind in order to avoid hand injuries:
  • Remove watches, rings, and bracelets before you start to work, especially if you work with moving machinery
  • Use gloves that are job-rated for the kind of work you do
  • Follow lockout/tagout procedures when cleaning, inspecting, or repairing machinery
  • Check tools and equipment for excess wear and dull cutting blades before using them
  • Do not ignore safety guards, which are on machines to protect you
  • Be aware of doorways and narrow spaces when you carry objects or push them with a handcart. Keep your hands where they can not get crushed
  • Keep your hands on the sides of objects when stacking them, not underneath, to avoid crushing your fingers
  • Use the right tool for the job, and be sure to use it correctly
• Clothing: hair and clothing can be snagged or grabbed by machinery, especially those with moving parts
  • Tie back long hair away from your face; hair still hanging below the collar must be tucked into a cap or hairnet if near moving parts
  • Remove neckties or other dangling clothing
  • Roll up long sleeves
  • Wear a safety apron to protect your body from flying particles of metal or wood

Other Hazards

Other potential hazards include the following:

• Back Safety: Before attempting to lift a heavy object, assess how to do so safely:
  • Is there a way to reduce weight or reconfigure the object(s) with handles?
  • Is the weight more than you can usually lift safely?
  • Is there a crane or other assisting device appropriate to the task?
  • Is there a safe way to share the lifting with another worker? Do not hesitate to ask your supervisor for a recommendation
  • Utilize lifting techniques that place minimum stress on the lower back
  • Use the OSHA Back Disorders website as a resource
• Musculoskeletal injuries: Proper workplace ergonomics can prevent such injuries, and Cornell has a free prevention program.
• Unexpected events or emergencies: see Emergency Response

During ERL running, formal Lab tours into CESR controlled areas will be allowed only if there has been a radiation survey demonstrating no hazard, and then only on the CHESS/West Flare/CLEO North route shown below. If the ERL is ON, tours shall not proceed into

1. the east-west corridor adjacent to ERL
2. the west tunnel beyond L5 (see floorplan)
3. the east tunnel beyond the first RF cavity (see floorplan)
4. the South side of CLEO
5. the L0 second level stairs/catwalk/etc.

If CESR interlocks are ON but CESR is OFF

• Tours are normally permitted only during access or down days when a radiation survey has been done and magnet power systems have been secured.
• A tour of the CHESS area may be possible if that area is in Bypass; check with the CHESS operator.
• In rare situations the possibility of a tour in specific CESR locations (most commonly only to the L0 catwalk, not beyond the chained-off section just south of the stairway to CLEO) during an interlock-set access should be discussed with the CESR operator, preferably well ahead of the tour time. Granting of permission for such a tour should not be assumed, may depend on several conditions, and specific limitations may be imposed.
• If interlocks are set, each tour participant would need a white key to enter the CESR-synchrotron perimeter and understand how to use it: each key holder is responsible for the timely return of the white key after the tour.
• At the CESR operator's discretion, only the guide would carry a white key and intentionally break the interlock on the way into a controlled area. In this situation both the guide and operator would independently keep headcounts prior to entering and after exiting the controlled area, verifying that everyone is accounted for.

First Aid

While we are fortunate to have help only minutes away, care provided by bystanders before professional help arrives could mean the difference between life and death. While no CLASSE employee is required to provide emergency care to the sick or injured, we encourage you to take First Aid and CPR classes so that you will know what to do if you want to help.

Most locations are equipped with First Aid cabinets that contain all the basic First Aid materials such as gauze, adhesive strips, adhesive tape, scissors, eye washes, breathing masks, cold compresses, iodine washes, cotton balls, triple antibiotic ointment, latex gloves, and cotton swabs. Each cabinet is equipped with a Red Cross First Aid Manual, but it is best to take a First Aid course and not rely solely on a First Aid guide. The First Aid cabinets can be found in the following locations: In Wilson Lab:

• first floor between the men's and women's bathrooms.
• first floor outside the accelerator tech room.
• second floor men's room.
• third floor kitchen.
• fourth floor on the first wall past the double doors in the vending machine area.

In Newman Lab:

• basement chemical room, on the ground floor.
• first floor, second floor, and third floor, directly above the drinking fountains by the elevator.

Immediate First Aid

The first few minutes after an accident can be the most important. Learning how to help yourself or others in an emergency situation at CLASSE is often a matter of knowing what to do while waiting for help to arrive. The following sections describe appropriate steps to take during emergencies, including how to care for injured people while waiting for help to arrive. The first and most important thing to do is to call 911 and notify Cornell Police that an ambulance, officer and/or the fire department is needed. Then, at Wilson lab, send someone to the loading dock, or at Newman lab, to the main lobby, to meet the responders and lead them to the victim.

• Remember that some people at the lab are trained in emergency medical care, and therefore may be more qualfied than you are to assist injured people during an emergeny. Therefore, do not feel obligated to assist during an emergency if you do not think you are qualified: untrained bystanders who attempt to help can make the problem worse.
• Before attempting to help anyone, be sure you are not putting yourself in danger. Common dangers include electrical wires, falling objects, chemicals, fires, and noxious fumes.
• Do not move sick or injured people unless their positions put them in immediate danger (i.e. fire, explosion, poisonous conditions). People who have suffered spinal injuries can be seriously hurt if they are moved.
• Cover victims with blankets to conserve heat.
• Keep emotional and noisy bystanders away from victims.
• Call the dispatcher back and update him or her on any changes in the patients' conditions.

If you decide to attempt First Aid, follow these steps first:

1. Determine responsiveness. Ask, "Are you OK?"
2. If there is no answer, have someone call 911
3. If you have been trained and believe you are qualified to do so, check the vicitm's ABCs:
   • Is the victim's Airway open?
   • Is he or she Breathing?
   • Is there Circulation?
4. Check for a medic alert tag.

Certain injuries require specific kinds of first aid treatment. The following sections outline appropriate procedures for several types of injuries.

Bleeding:

1. Have someone call 911
2. Use the latex gloves in the First Aid kits to avoid contact with infectious diseases.
3. Apply gentle, firm, direct pressure to the wound using a clean cloth or bandage. Maintain pressure for at least 10 to 15 minutes or until bleeding stops. Elevate the injured area.
4. Do not try to remove any embedded objects from wound.
5. If bleeding soaks through bandage apply more bandages and pressure, but do not remove old bandages from the wound.
6. Wait for help to arrive.

Electric Shock:

1. Never touch a victim who is still in contact with a power source.
2. Disconnect the power at the source. Within the building, shut off a main breaker. In the tunnel, activate the crash cord or crash button. This will shut off most high voltage power, except for a few sources which must be shut off manually.
3. If you can't turn off the power at the source, stand on a dry surface and disconnect the victim from the power source using a long, non-conductive object such as a broom or a rope.
4. Have someone call 911. If you have been trained and believe you are qualified to do so, check the ABCs (that the victim's airway is open, that he or she is breathing, and that he or she has circulation). If wounds are evident, cover them with sterile dressing.
5. Wait for help to arrive.

Chemical Burn:

1. Have someone call 911, and remember to say that chemicals are involved.
2. Remove any contaminated clothing. Never let the contaminated clothing come into contact with your own skin.
3. Flush the burned area quickly and thoroughly with lukewarm water for at least twenty minutes or until help arrives. Be sure to wash chemicals away completely.

Heat Burn:

1. If the victim is still on fire, attempt to extinguish the flames by pushing him or her to the ground and making the him or her roll over. If you can't get the victim to the ground or you can't get him or her to roll, try to use a wet coat, or preferably a fire blanket, to smother the flames. Fire blankets are located on the first floor of Wilson Lab, near the elevator and in the machine shop area.
2. Stop the burning process by removing ignited clothing and all jewelry from the burn area. However, never remove clothing from an individual who has suffered third degree burns. If extremities are burned, remove all jewelry beyond the burn where swelling could cause the jewelry to cut off circulation.
3. Have someone call 911
4. Do not apply creams, oils, sprays, or any other type of home remedy to burns
5. Give First Aid appropriate for the degree of the burn
6. Wait for help to arrive

First Degree Burns: Signs -- Red skin, pain, and mild swelling. Treatment -- Have someone call for help. Apply cool, wet compresses or immerse in cool, fresh water. Pat area dry and cover with a dry, sterile, non-adhesive dressing to prevent infection of the burned area. Elevate the burned area and protect it from dirt and friction.

Second Degree Burns: Signs -- Deep reddening of skin. Possible blisters, pain, loss of skin. Treatment -- Same as for first degree burns.

Third-Degree Burns: Signs -- Damage to all layers of skin, including nerves. May be painless. Skin is dry and leathery or charred. Normally surrounded by patches of first and second-degree burns. Treatment -- Have someone call 911. Check the victim's airway, breathing, and circulation if you have been trained and believe you are qualified to do so. If possible, cover the burn with dry, non-adhesive wrap. Do not use water. If the person's face is burned, have him or her sit up. Keep the burned area higher than victim's heart. Keep the person warm and comfortable, and watch for breathing problems and signs of shock. Wait for help to arrive.

Eye Injury:

1. Have someone call 911 for help.
2. Do not let the victim rub his or her eyes. If the victim has chemicals in his or her eye(s), quickly flush the eye(s) with lukewarm water for at least fifteen to twenty minutes. Eye washes are located in the chemical rooms at Wilson and Newman Labs and in the forklift area at Wilson lab. All First Aid cabinets should be equipped with an eye wash bottle. Position the victim so that no chemicals wash into the other eye.
3. If eyes have been exposed to chemicals, remove contact lenses. If a foreign object is in the victim's eye, do not remove his or her contact lenses unless rapid swelling occurs.
4. If a foreign object is in either eye, cover both of the victim's eyes to assist him or her in keeping them still, and do not attempt to remove the object.
5. Wait for help to arrive.

Heart Attack:

1. Call 911 for help
2. Calm and reassure the victim. If the victim is unconscious, see the following section for unconscious heart attack victims....
3. Encourage the victim to rest in a comfortable (perhaps seated) position, unless it is too painful to make such a transition. If the victim is having breathing problems, do not force him or her to lie down. It is more difficult to breathe when lying down
4. Loosen clothing around the victim's neck, chest, and waist
5. Keep the victim warm
6. Find out if victim has prescribed angina medication (e.g. nitro-glycerin) on hand, understanding that the victim may be unable to speak (e.g. the victim might point to a pocket if you ask "Do you have heart medicine?"). If you find medicine, assist him or her in taking it
7. If you have been trained and believe you are qualified to do so, check the victim's ABCs (airway, breathing, and circulation)
8. Stay with the victim until help arrives

Unconscious Heart Attack Victim:

1. Call 911 for help
2. Check for a medical alert tag
3. Stay with the victim until help arrives

University Closing

The Cornell administration ultimately decides when weather conditions warrant cancellations, evacuations, or closing of Cornell facilities. The Associate Vice President for Facilities and Business Operations makes this decision after he or she has consulted with the Cornell Police, the Superintendent of Ground Care, and local law enforcement agencies. When an impending natural disaster makes it necessary to close the University, you will be notified by local television and radio announcements. During business hours, supervisors will be notified of closings and cancellations, and they will then relay this information to their staff.

You can also check the Cornell University operating status web page.

Earthquake Response

Many of us do not know how to respond to an earthquake because they have been relatively rare (until the Virginia quake in 2011 which was felt in Ithaca). Hence the relevant information from the Cornell Emergency Earthquake Guide is reproduced here:

While earthquakes are not a high risk in the Ithaca area, they are possible here. If you feel the ground shaking, it could be due to an earthquake.

• If you are in an experimental area, move away from stacked radiation shielding blocks/bricks and unsecured equipment.
• Duck or drop to the floor
• Cover yourself under a piece of heavy furniture, a stairwell or a doorjamb (beware of the door swinging back and forth). If that is not possible, position yourself against an interior wall, protecting your head and neck with your arms. Keep away from appliances, large windows and heavy hanging objects.
• Hold on securely and stay covered until the shaking stops
• Evacuate the building as soon as the shaking stops, following your unit’s emergency plan and evacuation procedure
• If you are outdoors, move to a clear area away from trees, signs, buildings and electrical wires and poles. If you cannot get to an open area, take shelter in a doorway to protect yourself from falling debris
• If you are driving, pull over to the side of the road and stop. Avoid overpasses, power lines and other hazards. Stay inside the vehicle until the shaking stops. Once the shaking has stopped, proceed cautiously. Avoid bridges and ramps that may have been damaged.

After the shaking has stopped:

• Anticipate aftershocks, and plan where you will take cover from them
• Check for injuries. Give first aid as necessary. Remain calm.
• Avoid broken glass
• Check for fire - Take appropriate actions and precautions
• Check gas, water and electric lines. If they appear damaged, or if you smell gas, open windows and leave the building immediately
• Contact Facilities Customer Service at 5-5322 immediately (or 255-5322 from a cell phone)
• Replace all telephone receivers and use the phone for emergencies only
• Tune to an emergency broadcast station on radio or television. Listen for emergency bulletins
• Stay out of damaged buildings

Fire Zones at Wilson Lab*

Wilson Laboratory is divided into fire zones which include all CLEO and CHESS areas, the tunnel, and the West Modular Unit (aka CHESS trailer). The alarms go to the Ithaca Fire Department. There are annunciators in the CESR control room and at Barton Hall for the Cornell Police. The East Modular Unit (Computer Group & Electronics Shop) and Center Modular Unit (Stockroom & eXploration station), and Newman Lab each have their own fire alarm systems which are linked to Cornell but not to the Wilson system.

Fire Alarm Zone	Location
Zone 1	L1 (Tunnel)
Zone 2	L2 (Tunnel)
Zone 3	L3 (Tunnel)
Zone 4	L4 (Tunnel)
Zone 5	L5 (Tunnel)
Zone 6	Cross Tunnel
Zone 7	Synchrotron Hall (L0) & LS1
Zone 8	1st Floor - Room 101
Zone 9	1st Floor - CHESS, Electronic Lab, Stockroom
Zone 10	2nd Floor - Offices, Labs and Rm. 101 Sprinklers
Zone 11	6th Floor
Zone 12	3rd Floor - Offices and Labs
Zone 13	LS3 and LS2
Zone 14	4th Floor
Zone 15	5th Floor
Zone 16	Gas Alarm (manual alarm in CHESS & Control Room)
Zone 17	L0E (Machine Shop and Tech. Area)
Zone 18	New Addition - All floors

Fire Preparedness, Prevention, & Precautions

• Be familiar with primary and secondary escape routes: do not use the elevators; use stairways instead
• Keep hallways, stairwells, aisles, and exit doors completely clear at all times; do not block exits!
• Know where fire extinguishers are located and how to use them
• Don't depend on someone else to pull the fire alarm
• Have a plan for quickly powering down equipment you are using so as to leave it in a safe and stable state
• Plan to have important personal effects nearby or on your person so you can evacuate quickly, without a need to return if the building is closed for an extended period of time
• Plan to remove any potentially contaminated personal protective equipment (e.g. gloves, lab coat) prior to departing your workspace
• Near a fire, stay low to avoid inhaling smoke
• Feel every door for heat before opening it
• Close open doors as you evacuate the building to prevent the fire from spreading
• If you are on fire, do not run: STOP, DROP, & ROLL: drop to the floor and smother the flames by rolling
• If someone else is on fire, wrap him or her in fire blanket to smother the flames
• Do not smoke inside any campus building, nor within 25 feet of any entrance
• Know the flammability of the materials you are using and take appropriate precautions
• Do not use frayed electrical cords and do not overload circuits
• Do not plug an extension cord or power strip into another extension cord or power strip
• Exit signs must be lit and open to view
• Extension cords are only used for temporary needs; situations with insufficient outlets should be remedied by installing additional hardwired outlets
• Extension cords must not be strung through doorways, walls, over ceilings, etc.
• Extension cords, phone cords, cabling, and hoses must not be positioned so as to be tripping hazards
• Electric panels or junction boxes must all have proper covers
• Electrical receptacles and wiring must all be in good condition and not exposed
• Ceiling tiles must be in place to maintain the fire-stopping integrity of the ceiling
• Holes around wall or floor penetrations must be sealed with proper fire stopping material
• NOTHING should be hung from sprinkler piping
• Storage must be held back at least 18 inches from sprinkler heads
• Storage of chemicals, compressed gases, combustible or flammable materials must be done according to manufacturer's recommendations and good safety practice
• Any gas cylinder must be anchored to a wall to prevent it from tipping over
• Lab and storage areas should be neat and uncluttered; access for inspection should be easy
• Portable heaters are discouraged, but if present need space; separate adequately from flammables
• Use the correct wattage bulb in lamps and light fixtures

Fire Extinguishers

The use of a fire extinguisher can keep a small fire from spreading, assist in fighting a fire until help from the fire department arrives, and/or help provide an escape route. Fire extinguishers at CLASSE are generally located at door entrances and near stairwells. Do not attempt to use a fire extinguisher if you have not had training on fire extinguisher basics because you could injure yourself, others, or make the fire worse by improper use. Learn how to use them before a fire starts. Never put yourself in danger to fight a fire.

Origins of Ionizing Radiation

The electrons accelerated in the CESR bending magnets emit x-rays. Most of these x-rays are absorbed by the vacuum chamber walls, the tunnel walls, or the magnets. Higher intensity x-rays are created for CHESS in undulators and wigglers placed into the CESR ring for this purpose. X-rays can also be created in the processing of RF cavities.

Particles lost from any accelerator beam also cause radiation. Particles are lost when they collide with solid material or gas molecules or interact with another beam (as in CESR). They plow into the walls of the vacuum chamber and create a cascade of gamma rays and more electrons. Gamma rays are a higher energy cousin of x-rays. Some of the gamma rays hit atomic nuclei and knock out neutrons, most of which are stopped by thick concrete shielding. A few of the neutrons change some of the nuclei of accelerator components, such as targets and beam pipes, into radioisotopes. Radioisotopes, unlike RPE, can emit radiation after the accelerator is turned off. Fortunately, only a few locations at CLASSE have residual radioactivity at any detectable level. Areas of residual radioactivity usually include the linac, the linac snouts, the injection lines, the transfer lines, the inflector magnets, and occasionally at other places along the synchrotron or CESR. A survey for radiation is done every time the interlocks are to be turned off, and all areas above 2 mrem/hour at 30 cm are marked with signs.

In addition to x-ray radiation from accelerated electrons and lost beam particles, ionizing radiation at CLASSE can originate from several types of devices operated at high voltage. These include electrostatic separators in CESR, electron guns, and field emission equipment such as RF cavities.

Exposure to Ionizing Radiation

A key concept in radiation protection is ALARA (As Low As Reasonably Achievable), the concept that radiation exposures should be kept as low as is possible. Cornell policy aligns itself with the requirements of the Nuclear Regulatory Commission (NRC), which requires exposure to be limited to 5000 mrem per year for radiation workers (and, like Cornell, 100 mrem per year for non-radiation workers), as shown in the table below.

Regulator	Maximum allowed dose
	Radiation Workers	Non-radiation workers
US Nuclear Regulatory Commission	5000 mrem per year whole-body, 50000 mrem per year extremity	100 mrem per year
Cornell University	5000 mrem* per year whole-body (*notification at 1/40 annual limit per quarter (125 mrem) & investigation at 3/40 annual limit per quarter (375 mrem), pro-rated annual limit), 50000 mrem per year extremity	100 mrem per year

While most personnel will never be exposed to significant doses of ionizing radiation from sources at CLASSE, keep in mind the following principles of radiation protection to minimize your exposure:

• Time: Exposure equals exposure rate multiplied by time. Spending as little time as possible in a radiation area, waiting as long as you can after radiation-producing equipment has been turned off, and planning ahead will reduce your exposure.
• Distance: Maximizing the distance between you and the radiation source will significantly reduce your exposure.
• Shielding: Use appropriate shielding to protect yourself from unnecessary radiation. Lead shielding and source containers provide extra protection.

Remember and use the concept of ALARA and the principles of time, distance, and shielding to protect yourself from radiation.

If you believe radiation is entering an occupied area, notify all people in the area, vacate the area, and notify the CESR operator and the CLASSE Safety Director.

Controlled, Uncontrolled, and Exclusion Areas

Using the Cornell EHS Radiation Safety Manual definitions, the lab is divided into uncontrolled areas, where there is little possibility of radiation exposure, and controlled areas, where there is some possibility of exposure. In uncontrolled areas, the potential radiation dose rate must be below two mrem per hour and 100 mrem per year. No precautions need to be taken, and there is no radiation danger. All offices, building entrances, and most of (but not all) the following spaces are uncontrolled: Newman Laboratory, the Physical Sciences Building third and fourth floors, and the second and third floors of Wilson Lab.

The following are the controlled areas:

• CESR control room
• CESR tunnel and cross tunnel
• Linac (LS1)
• All of L0, including the pathway from East to West
• LS2 (above the linac)
• Rooms 101/102
• All CHESS hutches & caves
• Sector 7 area, where signed

The 3rd floor of Wilson and above have no controlled areas; the 1st floor hallway from the loading dock to CHESS is not a controlled area. There are no currently no controlled areas at Newman Laboratory or Physical Sciences Building, but you should be aware of signage for any area you enter because designations can change. If you are in a controlled area, you must wear a radiation badge (in fact, controlled areas are often called "badge areas"). Radiation badges are part of the personal radiation monitoring that helps us confirm the effectiveness of our protective measures. The large subset of the controlled areas at CLASSE that have potential for high radiation levels, designated as exclusion areas, are subject to more stringent rules: first, exclusion areas are separated from working and public areas by gates, radiation shielding, and an interlock system that prevents radiation-producing equipment from turning on. The radiation dose rate is expected to remain below two mrem per hour in CLASSE controlled areas that are not exclusion areas.

(NOTE: The cross-tunnel should not be used for casual passage to Tower Road.)

Interlock Systems

The major interlock systems at CLASSE are for CESR, ERL, and CHESS; each halts beam transport into certain areas if a perimeter is breached or certain required conditions are not met. Smaller systems can also have interlocks or "interlock chains" to guarantee proper procedures are followed prior to startup.

CESR interlock system

The CESR interlock system is an arrangement of gates and light beams that detect anyone walking into a radiation area at the wrong time. Electronic message boards near each entrance display the access and machine conditions. Signs and sounds provide information about the local environment. Before beam is injected from the linac, the CESR operator searches and resets all the interlocked area to guarantee only people with keys are inside. The keys prevent the accelerator from turning on. If you find yourself inside a radiation area when the warning sounds and the radiation area announcement comes over the PA system, do whichever of these three things is quickest (pull the crash cord, push a crash button, or break a light-beam interlock by stepping through it) to prevent beam coming on. When the machine is running, the board reads "synchrotron on" or "CESR on," and you may not enter. If you enter, you will interrupt the light beams, which sounds a loud siren and automatically shuts off CESR. If you break an interlock, go to the nearest beam phone to explain who you are and where you are to the CESR operator. The board will read "interlocks set" when the machine is ready to run. You may enter the area only if the sign also says "TAKE A KEY," and only with a key (because the key must be used to access controlled areas. Every person in a group must take a key and carry it until exiting interlocked areas, at which point it must be returned to its original location. (CESR cannot be turned on until all keys are returned. If you accidentally take a key from the building, call the CESR operator immediately and return the key to Wilson as soon as possible.) Never share keys. White keys allow access to all areas. Their storage box is located in the control room. While you have a white key in your possession, it is impossible for the linac, synchrotron, or CESR to generate or transport beams.

When taking a key, you should sign it out. If taking more than one key for a group, inform the CESR operator how many keys are being taken and write the names of the individuals receiving the keys on the sign-out sheet. If returning more than one white key, indicate the individuals for whom the keys are being returned on the sign-out sheet and inform the operator.

Colored keys available for access to specific areas are located near those areas. For example, CHESS West keys, which are yellow, allow access to CHESS West and are located in the CHESS area. To find out more about colored keys and the areas to which they allow access, speak with your supervisor or a CESR operator, or ask to see the short video (?) on the interlock system. If the sign reads "AREA SAFE," then the machine is completely off and the entire experimental area has been surveyed for residual radioactivity. Once the area has been declared safe, no keys are necessary and all experimental areas are open, but you must still wear a radiation badge (discussed later in this chapter) and pay close attention to posted warnings.

Radiation monitors outside the CESR exclusion area are interlocked to the linac and/or storage ring. If beam conditions deteriorate enough that significant radiation is leaking through (or over) the shielding walls, these monitors trip off the accelerator if the instantaneous dose rate exceeds 2 mrem/hr.

CHESS interlock system

The CHESS interlock system is described here.

Area Radiation Monitoring

Electronic monitors in experimental areas check levels of high energy gamma, low energy gamma, x-ray and neutron radiation. If any monitor detects a radiation level that is too high, the red light on the monitor blinks and an alarm sounds, and the linac and/or CESR is automatically turned off. Anyone in an experimental area such as CHESS should immediately evacuate that area until an operator is able to reset the trip.

In addition to electronic monitors, area survey radiation badges check the level of radiation both inside and outside radiation areas twenty-four hours a day. Survey badges record the amount of radiation in any given area that is monitored.

There is one Radiation Logbook for CESR/CHESS and one for ERL, which are kept in the CESR and ERL control rooms, respectively. They contain records of radiation survey results, changes in shielding, and other changes that affect exposure levels. The Radiation Safety Technician also keeps several other logs associated with radiation monitoring.

Radiation Shielding

Radiation shielding is strategically placed and monitored; no one should move any lead bricks or shielding without express permission of the CLASSE Safety Committee. Shielding effectiveness is only guaranteed up to a height of eight feet above ground, so do not stand on ladders, chairs, or tables within the experimental areas.

Request a badge

If your job entails routinely entering controlled areas, an assigned radiation badge with your name on it should be issued to you. To request a badge, fill out this online form.

Radiation Badges

Personal radiation monitors provide the final check on the effectiveness of Lab's protective measures against ionizing radiation. Each employee, student, CHESS User, or visiting researcher with a need to pass through or work near radiation will be issued a radiation badge, similar to this visitor badge. When replaced it will be stored at one of five locations, depending on where you work most; at Newman Laboratory, G-Line (staff only), or in one of the CESR, CHESS, or ERL control rooms. Visitor badges can be signed out, providing full identifying and contact information, which we are required by law to collect for CHESS Users, short-term visiting researchers, and any CLASSE personnel who have temporarily misplaced an assigned badge.

A radiation badge does not protect you from radiation or give you an immediate reading of the radiation level. Instead, it records accumulated radiation exposure over a period of one to three months, and is read out afterwards by the badge vendor. (Each employee's exposure history is confidentially maintained by CLASSE and Cornell University.) Clip your radiation badge prominently to the front of your clothing between waist and neck only if you plan to enter a controlled area (it may not record exposure correctly if placed inside a pocket).

Virtually all of our radiation badges, worn by those whose work brings them into controlled areas, register below ten mrem for each two-month wear period. The radiation exposure anyone receives at CLASSE is much smaller than that already received from from natural sources (300 mrem annual dose from rocks, cosmic rays penetrating the atmosphere, radon, and natural radioisotopes in the human body). Radiation exposures from man-made sources are: dental x-ray (25 mrem, one-time dose), abdominal radiography (150 mrem, one-time dose), medical brain scan (2400 mrem, one-time dose), and commercial air flight crew member (450 mrem, annual dose from cosmic rays unshielded by the lower atmosphere). The exposures reported by the badge vendor have already been corrected for natural radiation sources by comparing them with reference badges that are stored on-site but away from radiation; hence reported exposures will almost always be lower than the expected dose from natural sources alone in that period, and should correspond to the exposure in the workplace alone.

A second type of personal radiation monitor, one that does provide immediate visual readout of the accumulated dose, is the dosimeter. CLASSE uses both analog and digital dosimeters, as shown. Dosimeters are for use by a host or tour guide on behalf of visitors (see Giving Tours).

If you have had an assigned radiation badge at CLASSE (or elsewhere at Cornell) for more than one year, you can obtain your occupational radiation dose on record with EHS by clicking this link. Be aware that this dose is only the dose recorded by your radiation badge while you've worn it, and has already been adjusted to not include normal background radiation exposure. After you enter your NetId and password, a page with your information should appear (without the need for human intervention on the EHS end) after a short wait; with some browsers the pdf file does not appear but instead is downloaded automatically, so check your Downloads (or equivalent) folder.

Radiation Badge Mishaps

Radiation badges sometimes get lost or misplaced or mechanically damaged. Sometimes a user mistakenly wears a badge when getting a medical x-ray or traveling by air. You can mistakenly take someone else's badge from the rack or someone else can take yours. Rarely, badges report unusual readings due to damage or other malfunction (in this case, you will be informed of this after the badge has been processed). If anything unusual like this happens to your badge, please notify your supervisor or advisor if you are a Cornell staff or faculty member or student, the CHESS Operator if you are a visiting CHESS user, the CLASSE Safety Director, and the RSS immediately via the online Badge Mishap form (click on the preceding words). (If you were contacted first by someone else of a mishap, please respond via this form also.) It is essential that there be an accurate record of the circumstances and timing of the mishap to whatever specificity you can provide; it is also important that there be a record of your being informed of any problem with a badge. Where and when was the badge lost or irradiated? Do your best to reconstruct your activities on that day so that possible locations can be searched, and any exposures that may turn up later on a lost badge can be understood. If it can be agreed that a non-zero exposure on your badge was obtained while it was not on your possession, or not on the Cornell University campus, then the University's record of your occupational exposure should be corrected, and this form can be used to officially request such an action.

If for some reason the online form does not work, please cut and paste the form below into your email compose window, fill it out, and send it to the CLASSE Safety Director, the RSS, and your supervisor:

Personal Radiation Protection

If you work with radioactive materials or in radiation areas, you should be aware of some more personal safety protection devices:

• Portable survey meters: These are handheld monitors for gamma and x-ray radiation that provide instant readings. Remember to check the batteries before using one. The meters are available in the vacuum lab, the control room, the west RF transmitter, CHESS, and Newman 205. GM counters are professionally calibrated once a year. Some are used with special probes that give energy compensation and are thus highly accurate. Contact the Radiation Safety Specialist if you are unsure of which to use.
• Ring badge: Those who use intense sources to calibrate monitors, and others who demonstrate a need, can obtain ring badges from the Radiation Safety Specialist. Ring badge exposures will become part of your personal radiation records. You will be issued a set, one for each hand.
• Safety glasses and gloves: You should wear safety glasses and gloves if you are working around residual radioactivity. If you are handling sources, you may be required to wear them.

Pregnant Workers and Radiation Exposure

Because the human fetus has rapidly dividing cells and is highly sensitive to ionizing radiation, pregnant women should pay special attention to minimizing their ionizing radiation exposure. While CLASSE has developed a comprehensive Radiation Safety program of radiation monitoring, education, shielding, access controls, interlocks, and signage, it is nevertheless prudent for a pregnant worker at CLASSE to gather relevant information and understand the extra precautions available. To that end, CLASSE will provide confidential counseling and services upon request by any worker who is pregnant, or thinks she may be pregnant, and is concerned about exposure to radiation. The CLASSE Safety Director, CLASSE Safety Manager and/or the CHESS Safety Officer will generally provide these services, although with advance notice, counseling by a qualified staff member of the University Environment, Health and Safety Department can be arranged.

Radioactive Source Handling

LEPP owns about forty-five sealed radioactive sources, and CHESS owns ten. All of these sources are registered or on a permit from the University. All LEPP sources are sealed so that no one can touch the radioactive material directly. They are solid, covered in a permanent casing. Sources are stored in a safe when not in use. Any improperly used or unattended sources will be immediately returned to the safe.

The Radiation Safety Specialist (RSS) keeps an inventory of all sources, updating a logbook and card file each time a source is signed in or out. In cooperation with the Department of Environmental Health and Safety, the RSS handles ordering, receiving, moving, shipping, monitoring, and disposing of radioactive sources. The RSS also does periodic source surveys to ensure that all sources checked out are attended to and stored properly.

If you are interested in using or ordering a radioactive source, see the CLASSE Sealed Source (RPH) and the RSS for a personal orientation. Use of radioactive sources is restricted to approved people and locations. Undergraduate students may only sign out sources through their advisors or supervisors. Remember to wear personal protective equipment, such as gloves, when using radioactive sources. Also remember to use the principles of time, distance, and shielding to reduce your exposure to radiation. If you believe a source may be leaking, either because it looks damaged or because radiation has been detected where it is unexpected, notify everyone in the area and seek assistance from the RSS.

There are no federal regulatory limits on exposure to magnetic fields, so Cornell EHS has adopted prudent limits. Common units for magnetic fields are Tesla (T) and Gauss (G); 1 T = 10,000 G. For reference, the earth's magnetic field on its surface is about 0.6 G, some consumer electronic devices can generate magnetic fields up to 0.2 G up to an inch away, and medical MRI imaging typically involves a static magnetic field of up to 5 T (50,000 G). There is no evidence that short-term exposure to the static fields in MRI scans causes biological damage.

Frequency (Hz)	Exposure	Applies to	Cornell Limit (T)	Cornell Limit (G)
Static (<1)	Instantaneous	Extremities	5	50,000
Static (<1)	Instantaneous	Whole Body	2	20,000
Static (<1)	8-hour average	Extremities	0.6	6000
Static (<1)	8-hour average	Whole Body	0.06	600
Static (<1)	Instantaneous	Magnetic Implant (e.g. Pacemaker)	0.0005	5
Static (<1)	Instantaneous	Any public area	0.0005	5
f=1-300	Instantaneous	Hands and Feet	0.6 / f	6000 / f
f=1-300	Instantaneous	Arms and Legs	0.3 / f	3000 / f
f=1-300	Instantaneous	Whole Body	0.06 / f	600 / f
f=300-30,000	Instantaneous	Whole Body	0.0002	2
f=50-60	8-hour average	Whole Body	0.0005	5
f=50-60	8-hour average	Magnetic Implant (e.g. Pacemaker)	0.0001	1
f > 30,000	Instantaneous	Whole Body	Contact Safety Director

Personal Safety Protection

Wear proper safety protection when you work with electrical hazards. Gloves may be required (however, do not wear gloves when you are operating a revolving tool, such as a drill or saw). Safety glasses (prescription and non-prescription) and boots or shoes (of many types) are also available with purchase orders from the business office. Wear appropriate personal protective equipment when you are working with power tools, electricity of 50 volts or greater, or heavy equipment. Remember that watches and rings can cause fatal injury by acting as conductors. Remove all jewelry when you are working with power tools or near electrical hazards.

Know Your Equipment

Before beginning electrical work, check that your diagnostic equipment is in good working order, is properly calibrated, and covers the range necessary for the job. A small, hand-held digital voltage meter (DVM) is commonly used, but you must check the rating on the front of the DVM to ensure that the voltage with which you are working is under the meter's maximum rating. It is dangerous to use a meter on voltages that exceed its maximum rating.

Use proper testing equipment and accessories when repairing AC or DC powered equipment. Choose probes and modules carefully because they are rated for different peak voltages. Remember that peak AC voltage is about one and a half times the normally quoted RMS (root mean square) voltage. For instance, the typical 480 volts RMS AC power exceeds the 600 peak voltage rating of some meters. If you are unsure of which probe to choose for the equipment you are planning to work on, then you should use a DVM (with a rating higher than the highest possible voltage in the equipment you are working on) to measure the voltage first.

When you are in damp or wet areas, you must power line-operated equipment through a ground fault circuit interrupter (GFCI) . Test each GFCI before using it. Portable GFCIs are available from technical supervisors.

Before bench-testing a line-operated chassis, bond metal test benches to the ground and use a circuit breaker to ensure that the current is limited. A ground-fault circuit interupter may provide additional protection. You may also need a second person with you to satisfy the two-person rule.

Before testing or working on high voltage equipment or equipment capable of energy storage, note any posted warnings and then de-energize it with a grounding stick. The grounding stick, a metal wand with an insulated handle, is normally built in where needed (near outputs of DC power supplies, filter capacitors, etc.). Always disconnect the energy at its source before using a grounding stick, and, if possible, dissipate any stored energy. Be prepared to encounter stored energy when using a grounding stick. Wear safety glasses to protect your eyes from flying sparks while you securely attach the stick to the equipment. Keep the grounding stick in place so that voltages will not "float up", or come back, while you are working.

Lock/Tag/Verify

The Lock/Tag/Verify system is used to prevent equipment from being powered while someone is working on it. You must obtain the Wilson Lab LTV training session before using this procedure. Use the following steps when locking out machinery for maintenance:

1. Announce the shutdown
2. Shut off the equipment
3. Isolate the equipment from its energy source
4. Apply a lock to the disconnect or circuit breaker, and use a tag that states your name, the date, and the reason for the lockout
5. Dissipate any stored energy
6. Verify that the equipment will not operate, returning the controls to the off position

To restore power:

1. Remove all tools and other loose objects from the area; reinstall any guards
2. Notify all affected workers
3. Verify all controls are off
4. Remove the lock and tag and restore power

Never remove anyone else's lock and tag, unless following the process documented in the EHS Lock Removal Permit. To find out more about Lock/Tag/Verify, speak to your supervisor about attending a lockout/tagout training session.

See also the Cornell EHS Lock/Tag/Verify (LTV) page, writeup, and procedures.

Electrical Emergencies

For emergency contacts, see Emergency Numbers.

Common sense and the following basic guidelines will help you avoid serious harm in electrical emergencies involving fire, shock, or burns.

• Fire: See Fire Safety. If you see a fire, pull the nearest fire alarm. Switch off the power to the area if you can do so safely. In the CESR tunnel, it is often best to push a crash button or pull the crash cord to turn off power. If the fire is small and contained, and If you have been trained in fire extinguisher use, you may attempt to extinguish it; otherwise leave the area immediately and then notify the CESR Operator of the fire. If you attempt to put out a small, contained fire, use an extinguisher that is designated A-B-C, or B-C. (Never use just a Class A, or water extinguisher, on an electrical fire.) Always be on guard for the presence of hazardous voltages when extinguishing a fire. If the fire does not extinguish easily, leave the area and notify the CESR operator.
• Electrical Shock: If you find an unconscious person who is in contact with a power source, DO NOT, under any circumstances, touch the person or the wire itself. Disconnect the source of power first. Again, the best way to turn off equipment in the tunnel is to push a crash button or pull the crash cord. If you cannot turn off the source of power, then disconnect the victim from the source of power with a long, non-conductive object such as a broom or a rope. Designate a specific individual to call 911 and give the details of the accident. Once the unconscious person is disconnected from the source of power, use the ABCs of first aid to determine if the person is breathing. Stay with the victim, cover any wounds with sterile dressing, and wait for help to arrive.
• Burns: Treat electrical burns with care. If you or a co-worker has been burned, call 911 immediately for help. Refer to chapter ten for more emergency information.

The FDA Radiation Control for Health and Safety Act of 1968, 1040.10 separates lasers into the following hazard classes, which are based on power and/or potential to cause biological damage to eyes and/or skin. In the definitions below, "acute" means immediate (for visible light, faster than the human blink response of 0.25 sec, and potentially shorter times for other wavelengths) and "chronic" refers to exposure over a period of time of seconds to minutes. Distinctions are made between hazard level when viewing with or without optical equipment (the latter having the potential to concentrate power and therefore inflict more damage), and for visible or invisible wavelengths (i.e. whether the human blink response can be helpful in preventing eye damage). The designations do not cover hazard levels that exist when the device is disassembled during "service" (repair), when even more precautions should be taken.

• Class I: Not hazardous with or without optical instruments, because of low power and/or an interlocked enclosure; however, there are wavelength-dependent power limits for this class
• Class IIa: Chronic hazard only if viewed for more than 1000 seconds; applies to visible wavelengths only and power below 4 mW; emissions must be "not intended for viewing" (note that this class is sometimes erroneously referred to as "Class Ia", which does not exist)
• Class II: Not an acute hazard; applies to visible wavelengths only and continuous wave (CW) power below 1 mW
• Class IIIa: Either an acute viewing hazard (when viewed using optical instruments) or a chronic viewing hazard (when viewed without optical instruments for more than two minutes); CW power range is 1 to 5 mW and power density below 2.5 mW per cm^2
• Class IIIb: Acute hazard to the skin and eyes from direct radiation; CW power from 5-500 mW
• Class IV: Acute hazard to the skin and eyes from direct and scattered radiation, very likely to cause permanent damage; CW power above 500 mW

To make classification slightly more confusing, there is a newer, international classification developed by the IEC (International Electrotechnical Commission) that differs somewhat from the older FDA standard above; since 2007, either standard may be observed in the US. There are still levels numbered by increasing hazard, but arabic numbering (1-4) instead of roman numerals (I-IV), and instead of subclasses "a" and "b" there are subclasses "M", "R", and "B".

• Class 1: Not hazardous with or without optical instruments
• Class 1M: Hazardous only if viewing with optical instruments
• Class 2: Not an acute hazard; applies to visible wavelengths only and CW power below 1 mW
• Class 2M: Acute hazard only when using optical instruments; possible chronic hazard; applies to visible only
• Class 3R: Not an acute hazard; applies to visible and invisible, CW power range is 1-5 mW
• Class 3B: Acute hazard for direct or reflective viewing; not a hazard for diffuse reflection or to skin; applies to visible and invisible and medium power; CW power from 5-500 mW
• Class 4: Acute hazard for direct or indirect viewing; applies to visible and invisible and high power; CW power above 500 mW

A comparison of the FDA and IEC classification schemes can be found here.

General comments on laser use

Class 2 (or class II in the old classification system) lasers should be used whenever possible. The output of these lasers is limited to 1 mW, which is sufficient for many purposes (such as alignment), but they are considered safe due to the blink reflex, which limits exposure to about 0.25 s. Users of class 2 lasers should be aware, however, that intentional suppression of the blink reflex can lead to eye injury. Users should not stare into the beam. Alignment lasers may be required for alignment of an x-ray flightpath at CHESS, which is generally at about eye level; in such cases, special care should be taken to prevent exposure to unaware persons outside of the hutch.

Although lasers producing 5 mW output (class 3R, or class IIIa in the old classification system) are commonly marketed as hand-held laser pointers in the United States, they are only considered safe when handled carefully and with restricted beam viewing. These lasers should only be used when class 2 lasers are inadequate. Due to the fact that these lasers are generally mounted in a fixed position, possibly at eye level, the risk of injury is much greater than with a hand-held laser. Use of class 3R and IIIa lasers in a fixed position should be treated as hazardous. A standard operating procedure will not be required, but the Laser Safety Officer (LSO) or his/her delegate should approve their installation. The laser output must be contained within a well-defined nominal hazard zone (NHZ), for example, an x-ray hutch or other room, and a sign must be posted outside the NHZ indicating the nature of the hazard. It will not be necessary to enclose the NHZ with a laser safety curtain for a class 3R or class IIIa laser, but it is the user’s responsibility to restrict laser radiation exposure to within the NHZ.

Class 3B (IIIb) and class 4 (IV) lasers present significant hazards, and require special operating procedures and LSO approval before use.

Lasers that are not labeled with a classification or output power cannot be used without approval from the LSO.

Lasers at CHESS

See the page on Lasers at CHESS.

Lasers for ERL

Lasers for ERL Phase 1 are located in Wilson Lab, Rooms 141A and 143, adjacent to the ERL control room. The laser beam, which undergoes several stages of amplification, shaping, and wavelength shifting on laser tables in the two rooms, is transported through the wall between 141A and 143 and later through the wall to L0 to another laser table, and from there to the electron gun nearby. The lasers range in classification up to class IV (4), and protective measures in both rooms assume the maximum hazard in either. Rooms 141A and 143 both have access restricted to authorized personnel and are signed accordingly. These rooms are protected by keypad entry locks; for unauthorized emergency access (e.g. by fire investigators), the doors can be forced open, and this action shuts down the lasers. A multi-point interlock system is in place, which, depending on where a trip originates, can shut down front-end laser components, close the beam stop between 141A and 143, and/or close the shutter between 143 and L0. Several crash buttons are located in both rooms.

A laser system is also set up in the rear of Room 128 for the gun/photocathode studies to be conducted there. The laser room is located within the radiation exclusion area and is therefore interlocked to the light beam marking this boundary; in addition the door itself is interlocked to the laser system power. Equipment and required precautions are similar to those in Rooms 141A/143.

In routine operation, light beams and optical elements not on laser tables are completely enclosed in sealed, opaque rigid tubing. On laser tables, beams are frequently transported inside clad optical fibers, and the two L0 laser tables are covered. However, frequent changes on the L0 laser tables occur; hence the table covers are interlocked with microswitches so as to close the shutters from room 143.

Increased hazard exists during modifications to laser setups and alignment, for which a special bypass interlock mode and associated procedures exists. Authorized personnel have the generic EHS and ERL-specific laser training, and when necessary wear laser safety goggles appropriate for the wavelength and intensity.

L0 Vent

There is a vent system in the L0 experimental hall that can quickly exhaust any contaminated air outside the building. The L0 Vent buttons are located on the CHESS control panel, the West Flare, and the CESR Control Room. If you know of a leak of toxic or explosive gas, or suspect a large venting of cryogenic liquids in the Wilson Lab experimental areas, inform a CHESS operator or CESR Operator immediately, who will activate the L0 venting system. The operator will likely request evacuation of all personnel from the affected areas.

All cryogens are used near their boiling points. This means they are rapidly evolving gases at all times. The following shows both the extremely low boiling points of cryogens and the enormous amounts of gas these liquids could produce if they were to boil.

• Liquid Helium
  • boiling point of 4.2 K, -269 C, -452 F
  • volume ratio of liquid to warm gas is 1 : 757
• Liquid Nitrogen
  • boiling point of 77.3 K, -196 C, -321 F
  • volume ratio of liquid to warm gas is 1 : 696

Dewars are used to store and transport cryogenic liquids; gas boiloff is limited by keeping the liquid cold with thermal insulation and by allowing the volume to pressurize slightly. Dewars are protected against explosion by relief valves and burst disks. For a sobering account of what happens if such pressure relief is disabled, read this. For a harrowing account of what happens if a dewar is damaged, read this.

Liquid Helium (LHe)

LHe is used for equipment and experiments at very low temperatures (around 4-5 K). LHe cools the CTA magnet in the L0 blue room, CESR wiggler magnets, and superconducting RF cavities in CESR, ERL, and the HTC, as well as those at Newman Lab.

Like other cryogens, LHe is transported and stored in thermally insulated containers called dewars. Never tip LHe dewars when transporting them. Always move slowly and pull them only by their handles, not by the protective ring around the top. If you must crane-lift a dewar, attach the cables to the lifting lugs only.

Transferring LHe requires detailed understanding of the procedure, including the use of vacuum-jacketed transfer lines, which can be quite cumbersome and awkward. You must receive on the job training by someone familiar with the transfer process before attempting a transfer.

Both Wilson and Newman Laboratories have helium recovery/liquifaction systems which act to avoid helium loss by recooling evaporated helium into a liquid state. (In comparison, liquid nitrogen is relatively cheap, and no recovery system for nitrogen exists.) These systems contain refrigerators, large liquid helium reservoirs, liquid transfer lines, pumps, and large gaseous helium storage tanks which also act as a location for emergency pressure relief. These systems contain numerous safety features should be operated only by trained experts.

Liquid Nitrogen (LN2)

LN2 is sometimes used in the insulating jackets around LHe transfer lines and dewars to prevent rapid evaporation of LHe by radiant heating. LHe boils at a temperature of about 4 K and has a latent heat of about 20 joules per gram, whereas LN2 boils at about 80 K and has a latent heat of about 200 joules per gram. Room temperature is about 300 K. LN2 cools the thermal barrier necessary between LHe and room temperature.

Full LN2 portable dewars weigh about 600 pounds. Use caution when using and transporting them. Transport and tip them only with approved handcarts that can support their full weight. You should receive instruction from someone familiar with the process before filling or transporting a dewar.

Whereas the cost of helium makes the CLASSE helium liquification and recovery economical, liquid nitrogen is purchased commercially and delivered to large storage tanks (emblazoned with the "PRAXAIR" logo) outside Newman and Wilson. Liquid from these tanks is then piped via insulated transfer lines to the locations where large quantities are frequently or continuously needed. Small quantities of liquid N2 are sometimes useful, and small dewars can be filled by hand. Such filling requires the use of appropriate protective attire (see below).

Personal Protective Clothing

Avoid contact with cryogens or surfaces cooled to cryogenic temperatures to avoid cryogenic burns. Wear dry clothing when transporting or working near cryogens because the risk of cryogenic burns increases with wet skin or clothing. Wear long pants and long-sleeve shirts to avoid trapping any cryogens next to your body. You should also wear high-topped shoes, safety glasses or a face shield, and leather gloves. The gloves should be slightly large so you can remove them quickly in the event of a spill. Remove rings, watches, bracelets, and any other jewelry. Wear a waterproof tyvek suit, available in the stockroom, when there is a danger of being sprayed by cryogenic liquids.

If you are burned by a cryogen or a surface cooled to cryogenic temperatures, seek medical attention immediately (for anything other than minor burns, call 911). While waiting for help to arrive, bathe the burned skin with warm, not hot, water. Remember that the skin may be both frozen and burned.

Cryogens and Oxygen Depletion

Modest volumes of liquefied gases can displace much larger volumes of air when heated suddenly, leaving the air with a reduced oxygen supply. For this reason it is important to review the hazard in a given room or lab where cryogens are used and engineer appropriate safeguards. Examples where engineered controls were required include the liquid helium and liquid nitrogen used in the CESR tunnels and in the Newman SRF Processing Pits. Whenever cryogens are used in labs, rooms or other restricted volume areas, the volume of the cryogen used and the maximum delivery rate need to be compared to the volume of the use area and its ventilation rate. A simple summary should be discussed with the Safety Director.

Although the details of the use of cryogens are usually evaluated when there is a system design, there are guidelines that should be observed from the beginning of the design and included in the Safety Plan. Some of these include

• All normal exhausts of evaporated cryogens are vented outside the building or into a large, well-ventillated volume such as L0 at Wilson Lab
• Stored volumes and supply rates are limited to only what is needed
• All reasonably anticipated events that result in a venting of cryogen are engineered to vent outside the limited volume area. These would include quenches, simple vacuum failures, simple operational errors, and warm ups. This is usually accomplished by having a set of pressure relief systems that discharge into an appropriately sized and engineered vent line
• There is adequate ventilation
• Cryogenic storage vessels and delivery lines are protected against casual damage
• No trapped cryogenic volumes

Other Cryogenic Hazards

Cryostats are insulated containers that help maintain equipment at cryogenic temperatures. Each must be equipped with an adequate pressure relief system on any closed volume such as the insulating vacuum, any LN2 jacket, and the LHe vessel. Maximum working pressure of the cryostat must not be exceeded. Some dewars and cryostats use flexible "pigtails" which must be secured to prevent them from whipping around while cryogens are first being transferred through them.

Surprisingly, LHe and LN2, which are not flammable in their natural states, can pose fire hazards as cryogens. Because cryogens are so cold, they can cause oxygen from the surrounding air to condense on transfer lines as they flow through them. Concentrated oxygen is a fire hazard, so use insulated transfer lines to prevent condensation.

Generally gas should be ordered through the standard blanket-order contract, which should cover the vast majority of applications; speciality gases not available on the blanket-order system should be pre-approved with the CLASSE Safety Director to assure that proper training and controls are in place for storage and use. Gas cylinders not currently in use should be stored, capped and secure, outside Wilson Lab (just outside L0E) or in B29 Newman. Full stored cylinders are separated by flammable vs. non-flammable contents. Within each category, empties should be segregated as well. At Wilson, empty and full cylinders containing flammable gases are stored in cages on the driveway ramp; empty and full cylinders containing non-flammable stock gases are stored near the loading dock door.

Large-scale gas storage

A 13,000 gallon liquid nitrogen tank near the Wilson loading dock serves as the primary source of low pressure dry nitrogen (as well as of liquid nitrogen). Between the driveway and L0E there is a 25,000 gallon tank used for helium gas storage for the cryogenics system. Liquid nitrogen is stored for Newman Lab in a 6000 gallon dewar which is located nearby, adjacent to Olin Lab. Cylinders are also stored outside at Newman Lab near the loading dock. At PSB, gas cylinders in use are stored in designated areas near the laboratories; nonflammables in an interior hallway adjacent to all the third floor labs, and flammables in a separate room in the northeast corner.

Gas systems are concentrated in several areas of Wilson Lab. Other small systems are located throughout Wilson and Newman Labs.

Accelerator Gas Safety

Sulfur hexafluoride (SF6), which is both non-toxic and non-flammable, is the only gas used in the accelerator. It is a heavy gas that is used to stop electrical arcs from occurring. It is kept in a thirty-five-pound tank in the LS2 hallway east of the control room and is piped in copper tubing to the klystron tubes and into the Linac waveguides.

L0 Vent

There is a vent system in the L0 experimental hall that can quickly exhaust any contaminated air outside the building. The L0 Vent buttons are located on the CHESS control panel, the West Flare, and the CESR Control Room. If you know of a leak of toxic or explosive gas, or suspect a large venting of cryogenic liquids in the Wilson Lab experimental areas, inform a CHESS operator or CESR Operator immediately, who will activate the L0 venting system. The operator will likely request evacuation of all personnel from the affected areas.

Vacuum Lab Gas Safety

Several small containers of low-pressure gases are used in the vacuum lab. Some of the gases kept are hydrogen, carbon monoxide, methane, carbon dioxide, nitrogen, xenon, oxygen, neon, argon, and helium. Because the quantity of the gases used in the vacuum lab is so small, they pose little or no health or safety hazard. Most of these gases are used to check calibrations and for vacuum tests.

Welding Areas

Newman Lab, Wilson Lab, and the Annex all contain welding areas. Several different gases are used for cutting, soldering, and welding. These gases include oxygen, propane, nitrogen, argon, acetylene, argon/helium, and carbon dioxide. Show link to EHS Hot Work/Welding pageHide link to EHS Hot Work/Welding page: EHS Hot Work/Welding page

Always keep combustibles away from oxygen gas because the combination is highly flammable.

Always perform welding in an area where others are unlikely to be exposed to the harmful intense light from arcs, erecting opaque screens and/or placing signage warning of the hazard Make sure the welded object is allowed to cool before anyone can come into contact with it, attaching signage if it will be left unattended.

Chemical Training

If you and your supervisor agree your work involves significant use of chemicals, you may be asked to take one or more training sessions either at EHS, CLASSE, or both.

When we must use substantial quantities of dangerous chemicals such as in cleaning and etching high vacuum components and niobium super-conducting RF cavities, we use special facilities to do this work safely in our Chem Room in Newman Lab. Anyone who uses or works at CLASSE must receive special training from a CLASSE Chem Room Technician.

Safety Data Sheets

Safety Data Sheets (SDS) provide information about chemicals and other products. Each sheet includes information about one product's ingredients, usage, hazards and emergency procedures. Supervisors must provide any relevant SDS as part of preparing an employee or student to use a new product or chemical. Workers must read them to be prepared to use the product safely. As an example, examine this sulfuric acid SDS. Note that SDS do not all look alike because different manufacturers provide them.

SDS binders are located in the first floor receiving area in Wilson Lab and in the business office of Newman (Room 134) Lab. Smaller sets of chemicals commonly used in those locations are kept in the Newman chemical room (B50D) and some of the shops. When looking up a product, try the brand name and/or the product type. For example, Acme Ant Gel may be under Acme and/or under Ant Gel. Cornell EHS provides links to many searchable SDS websites on its SDS page. You can also locate them via web search engine, or at the SIRI site or the local CHESS site. If you cannot find the SDS you need, EHS can get it for you upon request.

After reading an SDS and learning about the hazards associated with a chemical or other product, be sure to discuss with your supervisor, or the area supervisor, your own plans for using the product and what precautions you plan to take. If you plan to use a chemical you've used before, but in a different location, please check with the supervisor of that area in order to ensure safety. If you have not used the chemical before, you or your supervisor must discuss your plans with the CLASSE Safety Director.

Chemical Warning Labels

OSHA requires that manufactured chemical products come labeled with the chemical name, hazard warnings, handling precautions, and manufacturer's name and address. Leave these labels in place and do not obscure or deface them.

There is a standard for such labels established by the NFPA (National Fire Protection Association). Quoting from the NFPA 704 FAQ on what is sometimes known as "the NFPA Diamond": "The standard provides a readily recognized, easily understood system for identifying specific hazards and their severity using spatial, visual, and numerical methods to describe in simple terms the relative hazards of a material. It addresses the health [left, blue], flammability [top, red], instability [right, yellow], and related [bottom, white] hazards that may be presented as short-term, acute exposures that are most likely to occur as a result of fire, spill, or similar emergency." Each colored diamond is numbered as 0 (no hazard), 1, 2, 3, or 4 (most hazardous). An example appears at right and a guide is shown below.

Common Chemicals and Hazardous Materials

No matter how harmless a chemical may appear, it can be dangerous. More accidents happen with common chemicals than with chemicals used for special purposes. Some examples of the hazards involving the following chemicals that are commonly used at the Lab:

Methanol, isopropanol, ethanol, and acetone are all common chemicals that are used throughout CLASSE for cleaning equipment as well as other purposes. All of them are flammable and can be explosive if used improperly. Excessive exposure by inhalation, skin contact, or ingestion can cause serious health consequences. They should be used in either a fume hood or a well ventilated area. Gloves and eye protection are required when working with these chemicals. None of these are drain-disposable. All must be treated as hazardous waste and disposed of by Cornell’s EHS.

Lead metal, unlike the "lead" in leaded gasoline, cannot be absorbed through the skin. However, it is harmful if inhaled or ingested because it gets into the blood stream. It is a cumulative poison that may cause decreased physical fitness, fatigue, sleep disturbance, headaches, abdominal pain, kidney damage, brain damage, and other severe conditions. Never cut, sand or machine lead bricks without special training. Always wear gloves (leather or rubber) and protective footwear when handling lead and wash your hands afterward. Sweep up any chips created by machining lead and give them to the rigging crew or EHS for recycling.

Beryllium: Beryllium is a silver-gray metal that has been produced for various industrial uses since the late 1950s. Inhalation of beryllium particles can cause a serious illness in certain people. This illness is chronic beryllium disease, or CBD—an irreversible and sometimes fatal scarring of the lungs. Do not touch Beryllium-containing components with bare hands.

Articles that may contain Beryllium include (but are not limited to):

• X-ray transparent containers, in particular as a part of specimen holders.
• X-ray windows on detectors (Bicron, Amptek), or beamline components such as flight tubes.
• High heatload compatible components.
• Ceramics used in electronics devices and other equipment.
• Springs, switches and relays.
• High-strength non-sparking tools.

These items present little risk of inhalation as long as they are not broken and no beryllium oxide is allowed to form. If your work involves the use of beryllium-containing items, find and follow the relevant standard operating procedures. Treat any broken or oxidized beryllium-containing article as hazardous waste.

Epoxies can harm eyes and skin, so wear safety glasses and rubber gloves and work with them only in well ventilated areas. Epoxies are especially dangerous when heated or when dust is created. Even epoxy vapors may be toxic.

Protective Clothing

Every chemical is potentially hazardous, so take simple precautions if you use any. Do not wear contact lenses, shorts, skirts, or open-toed shoes. Restrain long hair.

You must wear appropriate protection when you work with chemicals. Possible protective clothing you should use includes aprons, lab coats, boots, acid gloves, safety glasses, and face shields. After using reusable items, such as acid gloves, wash them thoroughly for the protection of the next user.

Eye Wash and Shower

Eye washes and/or showers are located at several locations in Wilson Lab, Newman Lab, and the Physical Sciences Building. If you are working with hazardous chemicals, read the SDS to find out if eyewashes and showers might be useful in the event of a spill, and familiarize yourself with the nearest such station's location and operation. The wearing of appropriate protective clothing should, in most cases, prevent the need for such situations.

Chemical Purchase and Disposal

If you plan to purchase any chemicals, keep in mind that disposal of both unused and waste chemicals costs money. Purchase only the quantities of chemicals you need. These chemicals have hazards associated with them. Obtain, read, and understand the SDS for the chemical before you purchase it. Use that information to plan and prepare to use it safely. Discuss your plan with your supervisor and a Chem Room Technician, or the CLASSE Safety Director. Give copies of the SDS to anyone who will be working with it and put a copy in the SDS binders.

As the purchaser, you are responsible for storing chemicals safely and labeling them correctly. Never leave chemicals in unlabeled containers. Aside from presenting unknown dangers to those working around the chemicals, identification and disposal of the chemicals involves a costly analytical process.

Disposal of chemicals requires environmental responsibility. Never pour anything down a sink or throw anything away before checking the chemical's SDS and Section 7 of the Cornell Chemical Hygiene Plan (available in the Newman and CHESS Chem Rooms, the Business Office, and near the Wilson loading dock). Chemicals clearly identified as non-hazardous in the plan should be marked "Non-Hazardous" and put directly in the dumpster. Custodians are not allowed to dispose of any chemical.

For hazardous chemicals that must be disposed of by EHS, follow the EHS instructions: obtain a Cornell Hazardous Waste tag from the Newman or Wilson chemical rooms or by requesting one from this email address, fill it out (leaving top copy with the waste) and make the pickup request online from EHS. Store the chemical in secondary containment with a copy of the SDS nearby. EHS should pick it up within 3 days. If you still have questions, check with your supervisor, the Newman or CHESS Chemical Room Technicians, the CLASSE Safety Director, or EHS.

Procedures for purchase and disposal of chemicals (and compressed gases) are different for the Physical Sciences Building. All materials not delivered through the building loading dock must be registered with the Safety Manager and bar-coded. Empties are dealt with by placing the bar code on this form and sending it as instructed on that form.

• LEPP Directory
• CHESS Directory