The DMSE Safety Primer

Index

• The DMSE Safety Program
  
• Emergencies and First Aid
  
• Basic Elements of Laboratory Safety
  
• Chemical Hygiene
  
• Electrical safety
  
• Cryogenic safety
  
• Fire safety

THE DMSE SAFETY PROGRAM

Introduction

Unfortunately, we tend to think of safety only after an accident. Laboratory safety, however, deserves and requires the same planning and attention that we give to research and teaching; it must not be an afterthought. There are both civil and criminal legal consequences of liability; and there are federal, state, and local laws that codify and regulate safe practices and environmental hazards. The details in the regulations that govern safety, environmental hazards, and waste disposal are changing and evolving, but the principles that underlie the approaches to these problems have not changed: when we are in the laboratory, we must think about what we are doing, we must be aware of the dangers, and we must know what to do if an accident occurs.

This Safety Primer is not intended to be an all-inclusive treatment of laboratory safety; such a document would be extremely large. The Primer is condensed from a number of larger documents, and is a summary of fundamental safety procedures all workers must know. It is intended as a first step in what must become a continuing education and concern with safety. Each laboratory situation has its own specific safety rules and procedures, and these must be added to the general information included here. Information in this manual is supplemental to that in other useful sources, such as the DMSE Chemical Hygiene Plan, and the MIT Accident Prevention Guide .

Responsibilities

Employees, Staff, Students, and Visitors

All students, visiting scientists, employees of DMSE, and all personnel who use the Departmental laboratories are subject to DMSE safety procedures, as augmented by the specific procedures dictated by the individual Laboratory Supervisors (usually the DMSE faculty member in charge of the laboratory). When the laboratory itself does not have a supervisor (true in some central facilities), the worker's advisor or supervisor carries out these duties. Each laboratory user is expected to do the following:

• All laboratory workers, including faculty, students, and visitors must pass a safety test based on this Primer before using DMSE laboratory facilities. This test is administered to 3.081 students at the beginning of the term; others should contact the DMSE Safety Technician (Mr. Frederick Wilson, room 13-4078, phone 3-6866) to arrange an appointment.
• The Laboratory Supervisor is required to provide specific information covering the procedures of the particular laboratory involved. Both the worker and the supervisor must sign a form agreeing that this briefing has been carried out satisfactorily before work may begin.
• Access to a laboratory will not be approved, and UROP proposals will not be signed, until the user has passed the examination and provided an acknowledgment of the safety briefing that has been signed by both the user and the Supervisor.
• Workers are to conduct themselves in a safe manner at all times, following the rules outlined in this Primer and other appropriate sources of information. The primary responsibility for safety resides with the individual worker.
• Workers must insist that coworkers follow safe procedures as well, and should report persistent failure to do so to the Laboratory Supervisor, the Departmental Safety Officer, or the Department Head.
• Workers should notify the Laboratory Supervisor of unsafe procedures in the laboratory, and of means by which they feel safety could be improved.
• Workers must notify the Laboratory Supervisor of all accidents, and near-misses as well.

Laboratory Supervisor

Although the individual worker is ultimately responsible for his or her own safety, the Laboratory Supervisor must insure that all laboratory workers have the facilities and training needed to make safe conditions possible. The Supervisor's duties include the following:

The DMSE Safety and Chemical Hygiene Committee

The Departmental Safety and Chemical Hygiene Committee is appointed by the Head of the Department. The Departmental Safety Officer and the Departmental Administrative Officer are ex-officio members. Currently, the DMSE Safety and Chemical Hygiene Committee consists of:

Duties of the Safety Committee include:

• The Committee assists the Departmental Safety Officer in formulating policies and procedures for laboratory safety, and also assists in formulating the examinations required under the Plan.
• Each Departmental laboratory will be inspected twice yearly for compliance with safety procedures; these inspections are supervised by Mr. Kearney.
• The Committee will coordinate safety procedures with the Research Directors for the Center for Materials Science and Engineering (CMSE) and the Materials Processing Center (MPC).
• The Committee will also review accidents and other incidents that involve chemical hygiene and safety.

The MIT Safety Office and Medical Services

The Institute provides a number of central services concerning safety and health. The Environmental Medical Service (Room 20B-238, phone 3-5360) have professional staffs that can be called upon for advice and help on safety and environmental health problems. These staffs offer the following services to the Institute:

EMERGENCIES AND FIRST AID

Summoning Help

• PULL the FIRE/EMERGENCY ALARM closest to the emergency, and evacuate the Building. Each building has evacuation routes described on cards posted throughout the building, and you must be aware of these routes.
• DIAL 100 from a safe location, give your name, the location of the emergency, and describe the emergency as best you can. Stay on the phone until the police dispatcher hangs up.
• The evacuation instructions specify meeting places at which the building's occupants should gather. Laboratory supervisors should account for the members of their group, to determine if anyone is still in the Building. If you think someone is still inside the building, notify the Fire Marshal/Campus Police/Emergency Response Team.
• After the emergency, promptly report the incident to the MIT Safety Office (phone 3-4736, room E19-207).

Dial 100 for:

• fire
• toxic gas leaks
• Campus Patrol
• ambulance
• serious illness
• accidents

Dial FIXIT (3-4948) for:

• floods
• city gas leaks
• stuck elevators
• loss of heating
• loss of fume hood fans
• lost of electrical power
• loss of ventilation

Other Safety-Related Phone Numbers:

• Roylance, David - DMSE Safety Officer 6-202 3-3309
• Wilson, Frederick - DMSE Safety Technician 13-4078 3-6866
• Diffley, Raymond - MIT Safety Office 3-4736 E19-207
• Clifford, Robert - MIT Industrial Hygiene Office 3-0908 20C-204

Additional Resources:

• Medical Department (24 Hour Emergency) 3-1311 E23-189
• Medical Department 3-4481 E23
• MIT Safety Office 3-4736 E19-207
• Environmental Medical Services 3-5360 20B-238
• Biohazard Assessment Office 3-1740 20C-208
• Radiation Protection Office 3-2180 20C-207

First Aid

In a medical emergency, summon professional medical attention immediately by dialing 100. Provide first aid within the scope of your training while waiting for professional help to arrive. Be prepared to describe accurately the nature of the accident.

Use of Emergency Equipment

Everyone working in DMSE laboratories must know how to use emergency equipment such as spill kits, safety showers, and eye wash apparatus. Know where these items are located in your laboratories.

Thermal Burns

• If the burn is minor, apply ice or cold water.
• In case of a clothing fire, the victim should drop to the floor and roll, not run to a safety shower. A fire blanket, if nearby, should be used to smother the flames.
• After flames are extinguished, deluge the injured areas under a safety shower. Keep the water running on the injured areas for 15 minutes to remove heat and to wash off chemicals.
• Place clean, soaking wet, ice-packed cloths on burned areas, and wrap to avoid shock and exposure.
• Do not use a CO2 fire extinguisher on a person with burning clothing; this could cause suffocation or frostbite. Dry chemical extinguishers will create inhalation hazards and contaminate wounds. Pressurized water can aggravate burn injuries.

Chemical Burns

• For chemical burns or splashes, immediately flush with water.
• Apply a stream of water while removing any clothing that may have been saturated with the chemical.
• If the splash is in the eye, flush it gently for at least ten minutes with clear water.
• Wash in a direction away from the other eye.
• If the splash is on the body, flood it with plenty of running water.
• A shower, hose, or faucet should be used in an emergency.
• For chemicals spilled over a large area, quickly remove contaminated clothing while using the safety shower. Seconds count, and no time should be wasted for the sake of modesty.

Traumatic Shock

• In case of traumatic shock, or where the nature of the injury is not clear, keep the victim warm, lying down, and quiet.
• Wait until medical assistance arrives before moving the victim.
• Report all injuries to your supervisor and the MIT Safety Office.

BASIC ELEMENTS OF LABORATORY SAFETY

Planning experiments

• Plan ahead: Seek information and advice about hazards. Plan appropriate protective procedures, plan positioning of equipment before beginning any new operation. Know what to do to prevent an accident and what to do if an accident occurs. Do not begin an experimental procedure until the Laboratory Supervisor has discussed these safety issues with you.
• Each laboratory worker must know the use and location of all first aid and emergency equipment in the laboratories, shops, and storage areas.
• Each laboratory worker must know the location of nearby telephones for summoning fire fighters, police, emergency medical service or other emergency response services. The emergency number (100) must be posted at many places throughout the building, and on each laboratory telephone.
• Each laboratory worker must be familiar with all elements of fire safety: alarm, evacuation and assembly, fire containment and suppression, rescue, and facilities evaluation.

Conducting experiments

• All injuries, accidents, and "near misses" must be reported to the Laboratory Supervisor. An Accident Report must be completed as soon as possible after the event by the Laboratory Supervisor.
• All chemical spills are to be reported to the Laboratory Supervisor, whose directions must be followed for containment and cleanup. Laboratory workers should follow the prescribed instructions for cleanup and decontamination of all spill areas.
• Protect your ears. The healthy ear can detect sounds ranging from 15 to 20,000 hertz. Temporary exposure to high noise levels will produce a temporary hearing loss. Long term exposure to high noise levels produces permanent hearing loss. There appears to be no hearing hazard (although there are possible psychological effects) to noise exposures below 80 dB. Exposure above 130 dB is hazardous and should be avoided. Ear muffs offer the highest noise attenuation and are preferred for levels above 95 dB. Ear plugs are more comfortable and are applicable in the 80-95 dB range. If you suspect that a hearing hazard exists, notify Environmental Medical Services and get the sound level measured.
• Unattended operations that could be hazardous should be avoided. When such operations must be conducted, the Laboratory Supervisor must approve the experiment, and the following precautions should be considered: leave lights on; place an appropriate sign on the door that includes the names(s) and phone number(s) of personnel that can be contacted in an emergency; and provide for containment of toxic substances in the event of failure of a utility service (such as cooling water, ventilation, electrical power, etc.).
• Do not work alone when conducting hazardous procedures, so that someone is available to summon help if the need arises. Some laboratories, especially teaching laboratories, will require that no work be conducted when alone.
• If you are working alone at times other than normal working hours, you may wish to notify Campus Patrol (3-1212) of your location and activities so that a patrol officer can check frequently as to your safety and locate you if an emergency occurs or you should require emergency assistance.
• "Horseplay" is hazardous and will not be tolerated.
• Long hair and loose items of jewelry or clothing must be secured during work with rotating machinery.
• Each laboratory worker must be familiar with an approved emergency shutdown procedure before initiating any experiment.
• No deviation from approved equipment operating procedures is permitted.
• All laboratory aisles and exits must remain clear and unblocked.
• Obsolete and unused equipment and materials must be removed from the laboratory, either to storage or disposal.
• The instructions on all warning signs must be read and obeyed.
• Good housekeeping must be practiced in the laboratories, shops, and storage areas.
• Only chemicals (no food) may be placed in the laboratory refrigerators, which should be "laboratory safe." Ice from laboratory ice machines may not be used for human consumption or to cool any food or drink.
• Avoid eating or drinking in laboratory areas where laboratory chemicals are used or stored; hands should be washed before conducting these activities.
• Smoking is not permitted in MIT facilities.
• Handle and store laboratory glassware with care to avoid damage; do not use damaged glassware. Use extra care with Dewar flasks and other evacuated glass apparatus; consider shielding or wrapping them to contain chemicals and fragments should implosion occur. Use equipment only for its designed purpose.
• Glassware breakage and malfunctioning instruments or equipment should be reported to the Laboratory Supervisor. There will be no open flames or heating elements used when volatile chemicals are exposed to air.
• Personal items brought into the laboratory should be limited as much as is practical to those things necessary for the experiment.
• Safety laboratory practices prohibit the presence of young children and babies in areas that have a potential for exposure to radioactive materials, toxic or hazardous chemicals, infectious agents, or where the children are exposed to possible injury from a laboratory or other type of accident.
• Casual visitors to the laboratory are to be discouraged and must have permission from the Laboratory Supervisor to enter. All visitors and invited guests must adhere to all laboratory safety rules. Adherence is the responsibility of the person visited.

Compressed Gas Cylinders

• Compressed gas cylinders must be secured at all times. Proper safety procedures must be followed when moving compressed gas cylinders. Cylinders not in use must be capped.
• Do not use grease on gauges or connections on compressed gas cylinders.
• Only gauges that are marked "Use no oil" are used for oxygen cylinders. Do not use an oiled gauge for any oxidizing or reactive gas.
• Laboratory workers are never to play with compressed gas hoses or lines or point their discharges at any person.
• Do not use adapters or try to modify any gas regulator or connection on compressed gas cylinders.
• All gas cylinders are to be returned to the proper vendor. Some small lecture bottles are the non-returnable type which become a disposal problem when empty or near empty with a residual amount of gas. When ordering gases in lecture bottle size, be sure to order the gases in a returnable cylinder.

General Rules

Chemicals can have devastating effects on exposed workers, and chemical hygiene must be given special attention. DMSE has a Chemical Hygiene Plan describing these dangers and procedures for avoidance in detail. This section of The DMSE Safety Primer is condensed from that larger document, and provides an introduction to chemical safety. However, the DMSE Chemical Hygiene Plan must be easily accessible in all DMSE laboratories, and laboratory workers must read and understand those portions of it that pertain to their own situations. Additional information is available online from the MIT Industrial Hygiene Office.

The following general precepts should be followed by all laboratory workers for essentially all work with chemicals:

Knowledge of Hazard

• Lists of hazardous chemicals have been compiled by the Occupational Safety and Health Administration (OSHA), SARA, NIOSH and other agencies. These lists have been reviewed by the Industrial Hygiene Office and by the Departmental Chemical Hygiene Office; a modified compilation is provided in the DMSE Chemical Hygiene Plan. Principal Investigators must establish standard operating procedures for the use of any of the hazardous chemicals listed in Table 1 of that document.

• The identification and classification of hazardous chemicals used in each laboratory are the responsibility of the Laboratory Supervisor, and the Supervisor is also responsible for authorizing use of the chemical to individual laboratory workers.

• Each research worker using a chemical is responsible for knowing the particular hazards associated with use of that chemical. This information is contained on the Material Safety Data Sheets (MSDS) prepared by the chemical manufacturer, and includes the worker's Permissible Exposure Limit (PEL) to the material as well as other safety aspects. MSDS's for many chemicals are available from the MIT Safety Office and the Chemical Engineering Department Library, and many of these are also available from the Internet ( click here). The MSDS should be obtained from the supplier when new chemicals are purchased.

• Based on the information in the MSDS and the way in which the chemical is to be used, the research worker must be aware of the control methods that are required. These control methods encompass storage, use, and any disposal methods other than the normal pick up of waste chemicals by the MIT Safety Office. The research worker should review the safety data and proposed control methods with the Laboratory Supervisor.

• Under the direction of the laboratory Supervisor, each worker in the laboratory is responsible for proper storage, use, and disposal of all chemicals used by that worker, according to the control methods established as described in above. Any worker accepting laboratory space accepts responsibility for all chemicals in it. If other chemicals are found in the space, the Supervisor should be informed immediately.

Accidents and spills:

Avoidance of "routine" exposure:

Choice of chemicals:

• The use of the following five chemicals is illegal in the City of Cambridge, MA, and must not be brought onto the MIT campus. These chemicals are:
  • Soman GD - nerve agent
  • Lewisite - blister agent
  • Mustard HD - blister agent
  • VX - nerve agent
  • Sarin GB- nerve agent
• The signature of the principal investigator is required to purchase the following chemicals:
  • Ethyl Alcohol (Tax free alcohol)
  • Explosives
  • Hypodermic Needles and Syringes
  • Liquefied Petroleum Gases (LPG)
  • Nitrous Oxide Gas
  • Poisons
• Before a substance is received, information on proper handling, storage and disposal should be known by the user. No laboratory chemical should be accepted without a label that identifies the chemical's name, and an accompanying Material Safety Data Sheet.
• Use only those chemicals and/or quantities of chemicals for which the quality of the available engineering controls (e.g. chemical hood and ventilation system) is appropriate.
• Assume that all substances of unknown toxicity are toxic and minimize exposure to such substances as much as possible.

Personal protection:

• All containers must be labeled as to content, composition, and appropriate hazard warning: flammable, explosive, corrosive, toxic, etc. The laboratory worker's name and the date the container was filled must be on the label.
• Toxic chemicals will be exposed to the air only in a property ventilated hood. Flammable chemicals will be exposed to the air only under a properly ventilated hood or in an area which is adequately ventilated (airborne concentration will be less than the Permissible Exposure Limit ("PEL") specified by the appropriate OSHA standard).
• When airborne concentrations of chemicals are or could be of concern, consult the MIT Environmental Medical Service.
• The user should keep personal protective items clean. In case the user knows or suspects that the item has become contaminated, it should be promptly removed and cleaned prior to reuse. Any skin area that may have become contaminated should be promptly and thoroughly washed.

Use of a Hood:

• A chemical hood should be used for operations which might result in significant release (e.g. above the OSHA permissible exposure level) of toxic chemical gases, vapors or dusts.
• As a rule of thumb, consider the use of a hood or other local ventilation device when working with any appreciably volatile substance of unknown toxicity or with an airborne occupational exposure limit below 50 parts per million (ppm).
• Adequate hood performance should be confirmed before use. This can be done by checking the Vaneometer, warning light or checking with a piece of tissue. For the best chemical hood performance the user should keep the work area five or six inches behind the plane of the sash, keep the hood sash closed except when adjustments within the hood are being made, keep materials stored in hoods to a minimum and not allow such items to block or interfere with airflow. If you suspect that the hood is not working properly, contact Physical Plant (phone FIXIT).
• The hood should be kept "on" with the sash down when it is not in active use if toxic substances are stored in it, or if it is uncertain whether adequate general laboratory ventilation will be maintained when it is "off."

Waste Disposal:

• A label indicating "Chemical Waste" with the chemical name and concentration should be placed on each container of chemical waste by the user.
• The MIT Safety Office should be called to collect such chemical wastes and for answers to chemical waste disposal questions.
• Do not discharge to the sewer flammable liquids, acids or bases (unless the pH has been adjusted to a range from 6 to 10 and heavy metals are not present), toxic, malodorous, or lachrymatory substances or any substances which might interfere with the biological activity of the wastewater treatment plant, create fire or explosive hazards, cause structural damage or obstruct flow.

Protective Clothing and Equipment

• The Laboratory Supervisor will determine the type of personal protection needed in specific laboratories. The requirements will be posted clearly, and workers will be diligent in adhering to the guidelines.
• Eye protection worn when working with chemicals should meet the requirements of the American National Standards Institute (ANSI) Z87.1. This means that chemical safety goggles available from the Warehouse should be worn whenever there is a potential for chemical contact such as a liquid splash. When working with more than 10 ml of a corrosive liquid, a face shield should also be worn. Covering safety eyewear is equally important to the wearer of contact lenses. Additionally, employees are encouraged to inform their supervisors when contact lenses are worn, and medical personnel treating the individual in case of chemical contact, so that proper eye irrigation can be provided. For general laboratory work without the potential for chemical contact or splash, the routine use of goggles or safety glasses with side shields should be considered.
• When working with corrosive liquids, gloves made of a material known to be resistant to permeation and degradation from the corrosive chemical should be worn. For example, a neoprene glove provides excellent resistance against 10% nitric acid while an industrial latex glove provides only good resistance. With 70% nitric acid the same neoprene glove provides only good resistance and the use of an industrial latex glove is not recommended by the manufacturer. The MIT Safety Office can provide additional information on the chemical resistance provided by different gloves and protective clothing items.
• A laboratory coat should be worn when conducting laboratory activities when contamination is possible in order to reduce the potential for chemical contact and to protect street clothing. When significant potential for liquid contact exists the use of safety goggles, impervious gloves and an impervious apron over the laboratory coat should be considered.
• When working with allergenic, sensitizing, or toxic chemicals, gloves should be worn that are resistant to permeation by the chemical and inspected by the user for the absence of pin holes.
• Whenever exposure by inhalation is likely to exceed the airborne limits described in the Material Safety Data Sheet (MSDS) a chemical hood should be used; if this is not possible consult with your supervisor and/or the Environmental Health and Safety Office before doing any such work.
• Carefully inspect all protective equipment before using. Do not use defective protective equipment. Keep protective equipment clean.
• Laboratory users should ensure that they have in their laboratory an eyewash unit connected to the potable water supply. This eyewash unit should be operated periodically (at least quarterly) by the user to verify proper operation. Keep electrical wires/equipment away from t he area of the eyewash.
• Laboratory users should know the location of the nearest emergency shower.

Housekeeping

• Access to emergency equipment, showers, eyewashes, and exits should never be blocked by anything, not even a temporarily parked chemical, housekeeping or maintenance type cart and/or construction material.
• Original labels on containers of chemicals must be protected so that the identity of the contents and the hazards those contents present is known. When chemicals are transferred from the original container to a secondary container, a new label should be attached that shows the chemical name(s). In any event, at the end of each workday, the contents of all unlabeled containers should be labeled or are to be considered wastes and placed into a properly labeled waste container. If unlabeled containers of chemicals are discovered, properly label the container if the contents are known, or call the MIT Safety Office so that the material can be properly identified and disposed.
• All chemicals should be placed in their assigned storage areas at the end of each workday.
• All working surfaces and floors should be cleaned regularly. Always, consider the measures that should be taken to prevent injury to personnel entering the laboratory to clean, collect waste, repair or remove equipment, etc.

Procedure-Specific Safety Procedures

Procedures for Carcinogens and Highly Toxic Chemicals

For their protection laboratory workers must follow the additional procedures described in this section when performing laboratory work with any select carcinogen, reproductive toxin, substance that has a high degree of acute toxicity, or a chemical whose toxic properties are unknown (when using or handling amounts greater than a few milligrams to a few grams, depending on the substance).

Prior to ordering a "special chemical" the Laboratory Supervisor should determine how to comply with these additional safety requirements. The Laboratory Supervisor must specify the designated area(s) and post the boundaries clearly. Only those persons trained by the Laboratory Supervisor to work with the "special chemical" and informed of its toxicity should use the substance. Such work should be done in the designated area. All users of special chemicals should conduct their work in accordance with the principles outlined below:

• Use the smallest amount of chemical that is consistent with the requirements of the work to be done.
• Minimize personal exposure by the consistent use, as appropriate, of a chemical hood, properly selected gloves, safety goggles, and laboratory coat that is removed by the individual prior to his/her leaving the laboratory.
• Use high-efficiency particulate air (HEPA) filters or high-efficiency scrubber systems to protect vacuum lines and pumps.
• Work on a spill containment tray and/or absorbent pad to facilitate cleanup and decontamination in case of a spill.
• Prepare for disposal any wastes from work with "special chemicals" as recommended by the Safety Office.

Procedures for Flammable Chemicals

In general, the flammability of a liquid is determined by its flash point, the lowest temperature at which an ignition source can cause the chemical's vapor to ignite momentarily in air under certain controlled conditions.

• Liquids with a flash point below 100oF (37.8oC) will be considered "flammable liquids."
• OSHA standards and the National Fire Protection Association (NFPA) guidelines apply to the use of flammable liquids in the laboratory. Consultant advice on these Fire Safety Regulations is available from the MIT Safety Office.
• Quantities of flammable liquids in the laboratory should be kept to a minimum consistent with laboratory needs and fire code mandates. Flammable liquids or items from which flammable vapors can evolve (e.g. ether) must not be stored in refrigerators/freezers, since most are not explosion- proof or explosion-safe.
• Flammable liquids should normally be used only in well ventilated areas away from sources of ignition.
• Special fire hazard potentials should be assumed to exist whenever oxygen is in use and/or oxygen concentrations in air are elevated above normal levels.
• Always store flammable liquids away from oxidizers.
• Be aware that liquids with flash points at and above 100oF may also present a significant fire hazard in case of ignition.

Procedures for Reactive Chemicals

Reactive chemicals are substances which may enter into violent reactions with the spontaneous liberation of heat and/or gases too rapidly to be safely dissipated. This may result in the rupture of the container, an explosion, fire or the release of toxic gases/vapors.

Laboratory users should handle reactive chemicals with all proper safety precautions, including segregation in storage. For example, nitric acid (a good oxidizer) should not be stored with flammables. Water reactives should not be stored in a location where the item could get wet. Users should not mix for the first time even small quantities of such reactive chemicals with other chemicals without prior approval of the Laboratory Supervisor.

For hot perchloric acid digestions, use only a perchloric acid hood, or use special scrubbers approved by the MIT Environmental Medical Service. This is necessary because the condensation of hot perchloric acid vapors inside the hood can result in the formation of explosive compounds that are shock sensitive.

Picric acid is useful for revealing grain boundaries and carbides in steels; however, it becomes highly explosive when it crystallizes out of solution during long-term storage (picric acid anhydride is an explosive). Therefore, the solution should be discarded within one week of preparation. If picric acid crystals must be used, procedures should be established to keep the crystals moist with water. Dry picric acid crystals are a shock sensitive explosive.

Some chemicals on aging form reactive compounds. For example diethyl ether forms peroxides that may be violently explosive. Thus, ether has an expiration date. Limit quantities of such materials and have a notification system so that outdated quantities of ether are collected by the MIT Safety Office.

Procedures for Corrosive Chemicals and Contact-Hazard Chemicals

Corrosive chemicals are those substances that, by direct chemical action, are injurious to body tissues or corrosive to metals. Users of corrosive liquids should take special precautions so that direct contact does not occur.

Hydrofluoric acid (HF) is an important example of this class of chemicals. HF is worth particular attention because it is being used in several departmental laboratories, including a teaching laboratory, and because it has some unusually dangerous features. It is both corrosive and a toxic chemical that is absorbed quickly through the skin. Serious injury or death may follow exposure even in cases where the victim is not aware of a chemical burn.

Local first aid in the laboratory in the case of almost all chemical exposures is confined to washing, eye washing, and safety showers. The exposed person must then go immediately to the Medical department. Hydrofluoric acid is the exception. After the initial washing, HF Antidote Gel (Calcium Gluconate) must be applied immediately and massaged into the affected area. Then go to the Medical Department. HF Antidote Gel is available from the Environmental Medical Service (3-5360). This gel must be available within easy reach of the user, and the instructions must be read before this acid is used.

The clean up procedure requires that slaked lime be used for neutralization. This forms calcium fluoride, which is not soluble in water. The neutralized slurry should then be collected with an absorbent spill pad, and placed in a container for disposal by the MIT Safety Office.

Ventilation

Work with significant quantities of toxic chemicals that have low air concentration limits (Threshold Limit Value less than 50 ppm), or that have high vapor pressures, should always be done in a hood. At nights and weekends laboratory general ventilation is reduced and users should place special emphasis on performing in chemical hoods all operations that might release significant amounts of chemicals and/or contact Physical Plant (phone FIXIT) so that their general ventilation needs can be met.

Chemical hoods should provide a minimum face velocity of 90 feet per minute (average) at any working height that will be used unless a different face velocity is approved by the MIT Environmental Medical Service.

Laboratory employees should understand and comply with the following principles:

• A chemical fume hood is a safety backup for condensers, traps, or other devices that collect vapors and fumes. It should not be used to "dispose" of chemicals by evaporation unless the vapors are trapped and recovered for proper waste disposal. For a chemical fume hood to provide significant protection it must be used and maintained properly by the user;
• The work or apparatus inside the hood should be placed at least six inches behind the sash;
• The fume hood sash should be closed at all times except when necessary to adjust the apparatus that is inside the hood (when hoods have horizontal sliding panes, the panes should be kept closed);
• The hood fan should be kept "on" whenever a chemical is inside the hood, whether or not any work is being done in the hood;
• Personnel should be aware of the steps to be taken in the event of power failure or other hood failure (e.g. stop work, cover chemicals, close hood, notify Supervisor);
• Physical Plant and the Environmental Medical Service inspect hoods at periodic intervals to be sure they are working properly.
• Hoods should not normally be used as storage areas for chemicals, apparatus, or other materials.

Environmental rooms are NOT well ventilated and procedures carried out in such rooms should be carefully designed to minimize personal exposures.

Flammable Liquid Storage

Flammable liquids in quantities greater than 500 ml should be kept in flammable liquids storage cabinets. If such flammable liquid storage cabinets are not available, the flammable liquids should be kept inside cabinets and not left on the floor or counters. When flammable storage cans are used, never disable the spring-loaded closure. Always keep the flame-arrestor screen in place; replace the screen if it is punctured or damaged. Flammables should not be stored with incompatible materials like oxidizers or in refrigerators and freezers since most are not explosion-proof or explosion-safe.

Cabinets designed for the storage of flammable materials should be properly used and maintained. The user should read and follow the manufacturer's information and should also follow these general safety practices:

• Store only compatible materials inside a cabinet;
• Do not store paper or cardboard or other combustible packaging material with flammable liquids;
• The manufacturer establishes quantity limits for various sizes of flammable-liquid storage cabinets; cabinet should not be overloaded.

Eyewash Fountains and Safety Showers

All laboratories have been provided with an eyewash connected to the potable water system. Safety showers are located in the hallways. Users need to know the location and how to operate such devices.

Users need to periodically flush and check the functioning of their eyewash fountains and make sure that electrical wires and devices are clear of the eyewash. This should be done on at least a quarterly basis. Facilities Management periodically checks the emergency showers and verifies proper operation. Users are encouraged to report problems with such safety devices promptly to Facilities Management for evaluation and repair.

Be sure that access to eyewash fountains and safety showers is not restricted or blocked.

Respirators

• Persons requiring respirators to protect against chemical exposure must contact the MIT Environmental Medical Service, which will assist in:
  Selection of the respirator;
  Fit testing of the respirator;
  • Training on the use, care and limitations of the respirator; and
  • Employee medical certification to wear a respirator.
• Surgical masks are not to be used to provide respiratory protection against chemical overexposure.
• The wearing of contact lenses with full-face respirators is not permitted under OSHA regulations.

Vapor Detection

Odor should not be relied upon as a means of determining that inhalation exposure limits are or are not being exceeded. Whenever there is reason to suspect that a toxic chemical inhalation limit might be exceeded, whether or not a suspicious odor is noticed, notify the supervisor and/or the Environmental Medical Service. As an interim measure, laboratory use of the chemical should be stopped, or the use of the chemical limited to a chemical hood.

Chemical Waste Disposal

MIT Policy

Storage Area

Transportation

General Procedures for Waste Disposal

Protection of the environment makes the disposal of large quantities of chemical and solid wastes a difficult problem. It is in everyone's best interest to keep quantities of waste to a minimum. The following suggestions may help:

• Order as small a quantity of material as practical, even if you can get twice as much for the same money.

• Use only the amount of material that is needed for conclusive results.

• Avoid storing excess material, particularly if it is an extremely toxic or flammable material, just because you may want it in the future.

• Before disposing of unwanted, unopened, uncontaminated chemicals, check with others in your department who may be able to use them.

• When a researcher completes a research project or a thesis, he or she must label all unused chemicals to be kept by the laboratory.

Make sure all samples and products to be disposed of are properly identified, labeled with their chemical names, and containerized. You must clean up before you transfer within or leave MIT. You must submit a Departure Compliance Form to the DMSE Safety Office before you transfer within or leave MIT. For more information on identifying waste, see the subsequent sections on "Identification," "Unknown Waste," and "Paperwork."

Procedures For Specific Waste Categories:

• Organic solvents must not be put down the drain. Regulations that apply to MIT's sewer system prohibit the discharge of organic solvents to the sewer system. This applies to all organic solvents whether flammable or nonflammable, miscible or non miscible with water. Organic solvents should be placed in suitable containers (1 gallon maximum) where there is no danger that vapors or the liquid will escape. Containers shall be capped tightly, labeled prominently, and picked up by the MIT Safety Office .

• Mixtures of organic solvents that are compatible and combined in one container must be identified with an estimated proportion in fractions or percentages of each solvent in the mixture indicated.

• Many laboratory operations create neutralized acids and-alkaline solutions which may be put down the drain provided that they do not contain heavy metals or toxic contaminants. Concentrated acids and caustics, acids and alkaline solutions should be put into proper containers tightly capped, sealed with laboratory film such as "Parafilm M", labeled, and given to the Safety Office.

• Inorganic and organic solids in their original containers that are contaminated, old, or of questionable purity may be given to the Safety Office.

• Mercury must be removed from lab apparatus and put into jars or bottles before sending it to the MIT Safety Office. Broken mercury thermometers must be put into a jar or secondary container. Clean-up materials from a mercury spill may be containerized, labeled, and sent to the Safety Office. Any laboratory or department that is interested in sending mercury waste to be distilled and to receive a credit for the mercury must take the responsibility of getting the mercury waste to the proper vendor.

• Cyanide compounds, arsenic, lead, and heavy metal wastes should be placed in bottles and containers, sealed tightly, labeled, and given to the Safety Office.

• Alkali metals such as sodium and potassium should be placed in a suitable container, covered with Nujol (mineral oil), labeled properly, sealed so that there is no possibility of their coming into contact with water, and given to the Safety Office.

• Pyrophoric metals such as magnesium, strontium, thorium, and zirconium, and other pyrophoric chips and fine powders should be placed in a metal container, sealed tightly, labeled, and given to the Safety Office.

• Waste oil in quantities of less than 1 gallon may be sent to the waste oil chemical storage area or given to the Safety Office. Large quantities of waste chemicals to be removed from a laboratory may be more than a normal amount for the Safety Office to pick up, and the Laboratory Supervisor will be financially responsible for the disposal. Some examples are the wastes collected in drum lots from a research project, the clean-out of a laboratory of old reagents and chemicals which would be packed into drums, and the waste chemicals to be pumped out of a collection or storage tank.

• Transformer oil which may contain PCB's should be tested for PCB content. The responsibility of having the transformer oil tested and for the actual disposal rests with the department involved.

• Capacitors that contain PCB's are likewise the responsibility of the department involved. Information on possible disposal contractors can be obtained by calling the MIT Safety Office (X3-4736).

• Equipment containing PCBs should not be accepted in transfer from other institutions or from other departments within MIT. If you accept PCB-containing equipment, you also accept a very large toxic waste disposal bill that only escalates with the passage of time.

• Controlled drugs to be disposed of as waste must not be sent to the waste chemical storage area. The handling, recording, and disposal of controlled drugs are the responsibility of the department involved operating within the Bureau of Narcotics and Dangerous Drugs (BNDD) Regulations.

• Biological waste that may contain live viruses must not be sent to the waste chemical storage area. The disposal of biological wastes is handled in accordance with procedures for deactivation that have been established by the department involved and the Environmental Medical Service.

The Environmental Medical Service may be consulted if there is any question concerning the toxicity or packaging of any toxic wastes.

Identification

Unknown Waste Chemicals

Unknown waste chemicals cannot be accepted for disposal. Disposal contractors cannot accept or ship unknown waste. It is the responsibility of the Laboratory Supervisor involved to identify all chemicals; this may require polling laboratory personnel, students, and faculty members to ascertain the owner of such unknown waste and its identity. Ultimately, it may require the services of an analytical laboratory to analyze the waste. This can be dangerous particularly when opening containers of unknowns, so it must be emphasized constantly to laboratory workers to identify and label all waste chemicals and project products with a chemical name.

Packaging

Waste chemicals must be packaged and containerized in a manner which will allow them to be transported without danger of spillage, explosion, or escape of dangerous vapors. Wastes which have not been properly packaged and identified will not be accepted for disposal.

Paperwork

A packing list must be filled out by personnel in the laboratory or department that requests that the waste picked up by the MIT Safety Office . The packing list must be filled out with the quantity, chemical name, designation as a solid or liquid, and hazard associated with the waste, i.e., flammable, toxic, water-reactive, etc. Safety Office personnel will bring the packing list with them when they pick up waste chemicals.

RADIATION SAFETY

A number of acute and long term effects on humans have been related to exposure from various types of ionizing radiation. Radiation hazards arise when using radio-isotopes, lasers, x-ray generators and plasma torches. Each is hazardous in a unique way. A thorough knowledge of the device or the isotope that is to be used is mandatory. The precautions vary widely. Information pertaining to the particular hazard should be obtained from the facility prior to use, or from the Radiation Protection Office of the Environmental Medical Services. However, several precautionary procedures should always be followed:

• All work with radioactive material or equipment that produces ionizing radiation must be registered with the Radiation Protection Office of EMS and performed in accordance with the MIT Required procedures for Radiation Protection.
• Review with the Radiation Protection Office any potential exposures to non-ionizing radiation such as ultraviolet, visible, infrared, and microwave radiation.
• Clearly mark areas in which lasers, radiation, and ultraviolet or high intensity light sources are in use. Standard signs are available from the Radiation Protection Office.
• Wear appropriate eye protection when working with these sources.
• Be aware and alert to radiation hazards when working in or visiting a laboratory where radiation is generated.
• Class IIIb and class IV lasers require a written Standard (Safe) Operating Procedure (SOP), and registration with the MIT Radiation Protection Office.

ELECTRICAL DEVICES

Electricity is in constant use both within and outside the laboratory, so it is easy to forget that significant physical hazard or death may result from its misuse. With direct current, a male can detect a "tingling" feeling at 1 mA and the median "let-go" threshold (the current at which he cannot release the conductor) is 76 mA. For 60 Hertz alternating current, the values are 0.4 mA and 16 mA respectively. Women are more sensitive to the effects of electrical current than males; approximately 2/3 of the above currents is needed to produce the same effect ("Electrical Hazards 5.1," Technical Information, MIT Safety Office). Higher currents produce respiratory inhibition, then ventricular fibrillation, and ultimately cardiac arrest.

Although minute electrical shocks are generally considered annoying rather than harmful, such shocks constitute an ominous warning of the presence of potentially hazardous conditions. The device in question should be disconnected immediately and the cause ascertained by a person competent in such matters. Work on electrical devices should be done only after the power has been shut off in such a manner that it cannot be turned on accidentally. Internal current-carrying devices such as capacitors must be discharged.

All "home-made" electrical apparatus should be inspected and approved by someone competent in electrical circuitry before being placed in service.

Observe the following rules when working with electrical equipment:

• Ungrounded wiring and two-wire extension cords are prohibited. Worn or frayed extension cords or those with broken connections or exposed wiring must not be used. All electrical devices must be grounded before they are turned on.
• Extension cords are for temporary use, and are not to be used n place of permanent wiring.
• Volt Limit: Untrained persons may not work on live equipment carrying potentials greater than 50V.
• Use only tools and equipment with non-conducting handles when working with electrical devices.
• If you feel an electrical "tingle" while working with a piece of laboratory equipment, disconnect it and consult with your supervisor. In the U.S., three-terminal (115 V AC) electrical wiring should conform to the following color code:
  • White = neutral wire
  • Black = live/hot wire
  • Green = ground wire
  (When working with existing wiring, do not trust that this color scheme has been used correctly.)
• Do not short circuit the leads to a battery. Without a fuse, the internal resistance of the battery will cause it to heat and possibly explode. Dangerous arcs or flashes may also be produced.
• A ground-fault interrupter does not assure protection against electrocution.
• All current transmitting parts of any electrical devices should be enclosed.
• When checking an operating circuit, keep one hand either in a pocket or behind the back, to avoid grounding yourself.
• Maintain a work space clear of extraneous material, such as books, papers, and clothes.
• Never change wiring with the circuit plugged into a power source.
• Never plug leads into a power source unless they are connected to an established circuit.
• Remove rings, watches, or other such jewelry before working on electrical circuits.
• Avoid contacting circuits with wet hands or wet materials.
• Wet cells should be placed on a piece of non-conducting material.
• Check circuits for proper grounding with respect to the power source.
• Do not insert another fuse of larger capacity if an instrument keeps blowing fuses. This is a symptom requiring expert repairs.
• Keep the use of extension cords to a minimum and cords as short as possible. Tie off excess cord out of pathways.
• Do not use or store highly flammable solvents near electrical equipment.
• Multi-strip outlets should not be used in place of permanently installed receptacles.
• Keep access to electrical panels and disconnect switches clear and unobstructed (three feet of floor space).
• Make certain that all electrical equipment (lamps also) is properly grounded.
• Be alert and aware of the dangers inherent in high voltage equipment.

In the event of a small electrical fire:

• Turn off the power source and unplug the equipment.
• Do not turn on the circuit until the cause of the fire has been established and the fault corrected.
• Report the fire to the Safety Office.

FIRE SAFETY

Emergency Procedures

Do not try to fight a fire yourself if you are uncertain of being able to handle it; call for help.

If a fire starts, call for assistance by pulling the nearest fire alarm box, and evacuate the building (do not use the elevators). DIAL 100 from a safe location and give what information you have. Do not return to the building unless permitted to do so by the Fire Department.

If your clothes ignite, "stop, drop, and roll" to smother the flames. Do not run; running only intensifies the flames. When fire blankets are readily available, use them to wrap around yourself to aid in putting out the fire.

Precautionary Procedures

Know the location of fire exits, fire alarm pull stations, fire blankets and extinguishers. Each laboratory should be equipped with an extinguisher or extinguishers. Fire extinguishers are primarily for fire fighters.

In rooms where the air flow is high, a natural gas leak could occur undetected. If there is one or more fume hoods in a lab, check for leaking valves by brushing a soapy liquid around the valve stem and over exit hole. If you see any bubbles in the liquid, call Frederick Wilson (13-4078/X3-6866) and Physical Plant (FIXIT) to report the leak.

Keep all fire doors closed at all times.

Do not block access to fire escape routes.

Neatness prevents many fires. Fire spreads much faster when it has cluttered waste materials to feed on. Oily rags, waste, or papers improperly stored are important causes of spontaneous combustion. Store these materials in covered metal containers.

The informational document Guide to Classes of Fires provides some guidance on firefighting methods.