MSDSs

5.0 GENERAL LABORATORY SAFETY

Working safely in a laboratory requires having the proper containment equipment and engineering controls, wearing appropriate personal protective equipment, using proper work practices, knowing safety information for the materials and equipment used, and following safety instructions and laboratory protocols.

The general safety information in this section is provided to assist investigators and supervisors in planning work and guiding those actually carrying out procedures.

Because each laboratory situation is different, judgment is required in interpreting general concepts for individual settings. The Laboratory Safety Profile provides specific information for individual laboratories. If you have questions or concerns about implementing general safety concepts or specific safety procedures, consult ORS.

Some laboratories contain more than one type of hazardous material. For example, biochemistry laboratories may work with chemicals, biological agents, and radioactive materials. In such cases, the protective equipment and work practices to be used are those that provide protection against the most hazardous agent or meet the most stringent legal requirement.

Handwashing is a primary safeguard against inadvertent exposure to toxic chemicals or biological agents. Always wash your hands before leaving the laboratory, even though you use gloves. Wash your hands after removing soiled protective clothing, before leaving the laboratory, and before eating, drinking, smoking, or using a rest room.

Wash your hands periodically during the day at intervals dictated by the nature of your work. Wash with soap and running water, with hands held downward to flush the contamination off the hands. Turn the tap off with a clean paper towel to prevent recontamination, and dry your hands with clean towels.

Confine long hair and loose clothing when in the laboratory to keep them from catching fire, dipping into chemicals, or becoming entangled in moving machinery. Avoid wearing finger rings and wrist watches which may become contaminated, react with chemicals, or be caught in the moving parts of equipment.

Remove laboratory coats and gloves before you leave the laboratory to prevent spreading contamination to other areas. Keep a clean spare coat to wear outside the laboratory. Do not wear gloves outside the laboratory.

Personal protective clothing and equipment shall be used and maintained in a sanitary and reliable condition and shall be cleaned regularly to avoid spreading contamination. Noncontaminated laboratory coats can be cleaned by any laundry service/dry cleaner. Contaminated coats should be sent to the University approved vendors. See the ORS Web page at http://www.research.northwestern.edu/ors/labsafe/laundry.htm.

Laboratory coats shall never be washed at home. Regular clothing that is suspected of being contaminated shall be evaluated by ORS for a proper decontamination or disposal method. It shall not be washed with or come into contact with other personal laundry.

5.2.1 Clothing. Cover unprotected skin whenever possible. Suitable clothing shall be worn in the laboratory; shorts are not appropriate. Clothing may absorb liquid spills that would otherwise come in contact with your skin. Long sleeves protect arms and shall fit snugly, especially when you are working around machinery. Wool affords more protection from flash burns or corrosive chemicals than cotton or synthetic fabrics. Synthetic fabrics may increase the severity of injury in case of fire. Cotton is less prone to static electricity buildup than nylon or other synthetics.

Wear substantial leather shoes in the laboratory to protect against chemical splashes or broken glass. Do not wear sandals, cloth sport shoes, perforated shoes, or open-toed shoes. If you clean up a spill from the floor, you may need the added protection of rubber boots or plastic shoe covers. Steel-toed shoes are required for handling heavy items, such as gas cylinders or heavy equipment components.

Aprons, laboratory coats, gloves, and other protective clothing, preferably made of chemically inert material, shall be readily available and used. Laboratory coats are essential to protect street clothing from biological agent aerosols or chemical splashes and spills, vapors, or dusts. For work involving carcinogens, disposable coats may be preferred. For work with mineral acids, acid-resistant protective wear is desirable. See Table 5.1 for properties of protective clothing materials.

When the potential for fire exists, consider wearing a laboratory coat specifically designed to be flame retardant. Several types of flame-resistant clothes are available from safety suppliers. A low-cost option is a disposable cotton coat that has been treated with a flame-resistant material. The treatment slows combustion and provides an additional level of protection from fire and heat. However, repeated washing degrades the chemical treatment and compromises fire protection.

More durable flame-resistant cotton laboratory coats are also available. One brand, Indura, employs a special finishing process that improves washability over standard fire-resistant cotton fabrics. A fabric known as Nomex provides the best protection against flame hazards. This material has a structure that thickens and carbonizes when exposed to heat. This unique characteristic gives Nomex lab coats excellent thermal protection. Because the characteristics of the material are inherent to the fiber, repeated laundering does not change the thermal protection capabilities. The drawback is that these coats are very expensive relative to treated and untreated cotton coats.

5.2.2 Eye Protection. Eye protection is mandatory in laboratories because of the obvious hazards of flying objects, splashing chemicals, and corrosive vapors. Eyes are very vascular and can quickly absorb many chemicals. Regulations require protective eye and face equipment where there is a reasonable probability that using them can prevent injury. Eye protection shall be required in all laboratories where chemicals are used or stored. Eye protection is not interchangeable among employees and shall be provided for each individual unless disinfected after use.

Safety glasses with clear side shields are adequate protection for general laboratory use. Goggles shall be worn when there is danger of splashing chemicals or flying particles, such as when chemicals are poured or glassware is used under elevated or reduced pressure. A face shield with goggles offers maximum protection (for example, with vacuum systems that may implode).

Corrective lenses in spectacles do not in themselves provide sufficient protection. Regulations require that persons whose vision requires corrective lenses, and who are required to wear eye protection, shall wear goggles over their eyeglasses, prescription safety glasses, or goggles with prescription lenses. These options are also recommended for persons who customarily wear contact lenses. If contact lenses are worn, they should not be handled in the laboratory and shall be worn with regularly required eye protection, such as plastic goggles.

Wearing of contact lenses in laboratories. Recent studies have produced varying views on the issue of contact lens use in laboratories. Traditional safety lore claimed that contaminated aerosols or particulate matter would concentrate behind contact lenses and cause permanent eye damage. In contradiction to this assumption, some researchers have found that contact lenses may minimize injuries to the eye from metal particles, paint fumes, and chemical splashes from solvents and acids.

Table 5.1 Properties of Protective Clothing Materials*

*Based on manufacturer's claims.

From Chemical Safety Manual for Small Businesses, American Chemical Society, second edition, 1992.

It was once thought that chemicals are absorbed into the lens and concentrated, causing more significant irritation and possible burns. Instead, new information indicates that eyelid spasm seals off the area of the cornea under the lens. Also, contact lenses are probably beneficial because they provide far superior vision correction than spectacles. They give the same field of vision as the normal eye whereas spectacles reduce it. Theoretically, better sight may result in fewer accidents since distorted vision would be less of a potential factor.

An unresolved controversy rages among safety professionals, though it seems that evidence on the side of lens use acceptability is growing. In 1998, the American Chemical Society removed its prohibition against the wearing of contact lenses in labs. The University's policy is to allow each individual principal investigator or laboratory supervisor to enforce the rule which (s)he supports. PIs may choose to ban contact lens use from the lab or allow use of contacts with appropriate eye protection such as safety glasses or goggles.

If contact lenses are to be permitted, lab personnel shall be trained to understand that lenses may be difficult to remove in the case of a splash. Training should include the following warnings:

• Copiously irrigate the eye with water, as you would for any splash.
• Hold the eyelids apart and keep the eye open as wide as possible.
• Do not worry about losing the lens!
• If the lens cannot be removed quickly, use a suction-type contact lens remover.

PIs should consider having the suction removers available in the lab's first aid kit.

5.2.3 Gloves. Gloves are worn to prevent contact with toxic or biological agents, burns from hot or extremely cold surfaces or corrosives, or cuts from sharp objects. Skin contact is a source of exposure to infectious agents and toxic chemicals, including carcinogens. Many gloves are made for specific uses. For adequate protection, select the correct glove for the hazard in question.

A leather glove provides good protection for picking up broken glass, handling objects with sharp edges, and inserting glass tubing into stoppers. However, because they absorb liquid, leather gloves do not provide protection from chemicals, nor are they adequate for handling extremely hot surfaces. Gloves designed to insulate against hot surfaces and dry ice are not suitable for handling chemicals.

Inspect gloves for punctures or tears before putting them on. To prevent contamination of your hands or work surfaces, wash rubber or plastic gloves thoroughly with water before removing them. Pull off disposable gloves inside out and dispose of them according to the contamination hazard. Always remove contaminated gloves before leaving the laboratory. Always wash your hands after removing gloves, before leaving the work area, and before eating, drinking, smoking, or applying cosmetics.

The chemical resistance of rubber or plastic gloves varies greatly according to the glove material and the chemical handled. Consult ORS for informat ion before selecting and using laboratory gloves or see the sources listed below.

Specific information pertaining to resistance can be found in The Chemical Protective Clothing Performance Index Book, 2nd Edition by Forsberg and Keith (John Wiley and Sons, 1999). If you are unsure oif your gloves are compatible with the chemicals you are working with hyou should contact the manufacturer. ORS also provides additional resource information that can be used as a guide at http://www.research.northwestern.edu/ors/labsafe/glovelinks.htm .

Chemicals can eventually permeate all glove materials. Select glove materials resistant to the chemical being used, and change gloves periodically to minimize penetration. The chemical resistance of common glove materials varies according to the glove manufacturer, as manufacturers may vary the thicknesses and formulations of materials. Call the manufacturer to verify that a particular glove material is suitable for the chemical in use.

Latex Gloves. In practice, most labs tend to rely on latex as the staple for glove supplies for general laboratory use. Due to the prevalence of allergies to natural latex proteins, ORS recommends substitution of latex gloves with nitrile or neoprene ones. Although these alternate glove materials may vary from latex in the range of typical lab chemicals to which they are rated as resistant, they do exhibit longer breakthrough times for those chemicals to which all three are acceptable. This is an added benefit to the avoidance of allergies.

Be aware that there are notable exceptions in performance between these gloves. Nitrile offers no protection for acetone use but is the preferred protection over latex for ethanol, formaldehyde, and mineral oil. This variability is a convincing argument as to why it is important to carefully check resistance charts for specific gloves.

See the ORS publication "Allergic Reactions to Latex Gloves" at http://www.research.northwestern.edu/ors/labsafe/latex.htm for more information about latex allergies.

5.2.4 Respirators. When feasible, engineering controls shall be provided to minimize airborne hazards. If accepted engineering control measures are not available to prevent or protect against harmful levels of airborne contaminants, employers are required to provide respirators at no cost to employees and employees are required to wear them. Respirators are considered a last resort of protection against exposure to inhalation hazards after all practicable engineering options have been exhausted.

Persons desiring to use a respirator shall inform ORS and obtain information on the requirements. These requirements are mandated by the OSHA Respiratory Protection Standard and are described in the University's Respiratory Protection Program.

A hazard evaluation shall be conducted to determine whether the employee or student is required to wear a respirator or whether engineering controls can eliminate the hazard. If the need for a respirator is established, the wearer must register with ORS.

The potential respirator wearer must meet certain qualifications before being allowed to wear a respirator. A licensed healthcare provider (LHCP) shall review an annual, confidential medical questionnaire submitted by the wearer. Based on the questionnaire, the LHCP may recommend a physical examination. A medical history of respiratory or heart disease could preclude the use of a respirator.

ORS will select an appropriate respirator for protection against a given contaminant and evaluate it in terms of the range of contaminants to which an employee is exposed during a particular procedure. It is the PI or supervisor's responsibility to provide and pay for the respirator. Employees are prohibited from purchasing their own respirator.

Fit testing is required before the employee or student first wears the respirator and annually thereafter. Fit testing is necessary to establish that the chosen respirator seals to the face properly to prevent inward leakage of contaminants. Respirator wearers shall receive interactive training in respirator use, limitations, and care. The respirator shall be cleaned and disinfected on a regular basis and inspected before and after each use.

Respirators shall not be worn when conditions prevent a good facepiece-to-face seal, as with beard growth, sideburns, or dentures. With full-face respirators, temple bars on eyeglasses interfere with the sealing edge of the facepiece.

All laboratory protocols shall include basic safety precautions. These include personal hygiene, work practices, and the appropriate personal protective clothing and equipment needed to protect you from exposure to chemicals or biological agents. Each situation is unique, and safety aspects shall be assessed individually as described in your Laboratory Safety Profile. Some of the fundamental principles of laboratory operation are described below.

5.3.1 Housekeeping. Keeping things clean and organized helps provide a safer laboratory. Keep drawers and cabinet doors closed and electrical cords off the floor to avoid tripping hazards. Keep aisles clear of obstacles such as boxes, chemical containers, and other storage items that might be put there even temporarily. Avoid slipping hazards by cleaning up spilled liquids promptly and keeping the floor free of stirring rods, glass beads, stoppers, and other such items. Never block or even partially block the path to an exit or to safety equipment such as a fire extinguisher or safety shower.

Make sure that supplies and equipment on shelves provide sufficient clearance so that fire sprinkler heads operate correctly. There shall not be any storage within 18 inches of a sprinkler head.

Put ordinary wastepaper in a wastepaper basket separate from chemical wastes. Broken glass and other sharp items shall be disposed of in rigid, puncture-resistant containers to protect persons collecting the waste materials. Needles and syringes that are not contaminated may be sealed in a rigid, puncture-resistant container and placed in a regular waste receptacle. When discarding empty boxes or other containers bearing hazardous materials labels, the labels shall be defaced or removed before disposal. Contaminated boxes or containers shall not be disposed of in the regular trash.

Chemical wastes and unwanted chemicals shall be disposed of promptly and not left to clutter a laboratory. The procedure is described in Section 6.0. Infectious waste management is described in Section 7.0. Additional information on disposal of human body fluids or other potentially infectious materials appears in the Bloodborne Pathogens Program.

5.3.2 Cleaning Glassware. When cleaning laboratory glassware, wear appropriate gloves that have been checked for tears or holes. Avoid accumulating too many articles in the cleanup area around the sink; space is usually limited, and piling up glassware leads to breakage. Do not clean food containers in a sink that is used for cleaning contaminated glassware.

Many fingers have been badly cut by broken glass from glassware that was intact when put into the sink water. Handle glassware carefully and watch out for broken glass at the bottom of the sink. A rubber or plastic mat in the sink will help minimize breakage.

Avoid using strong cleaning agents such as nitric acid, chromic acid, sulfuric acid, strong oxidizers, or any chemical with "per" in its name (perchloric acid, ammonium persulfate, etc.) unless no alternatives are available. The prefix "per" signifies a state of completeness or extremity. In a chemical name, it denotes 1) a compound containing an element in its highest state of oxidation, such as perchloric acid; 2) the presence of the peroxy group (-O-O-), as in peracetic acid; or 3) exhaustive substitution or addition, as in perchloroethylene.

If you must use these substances for cleaning, you should be thoroughly familiar with their hazardous characteristics and use appropriate protective equipment. Flammable solvents such as acetone should be used in minimum quantities for cleaning and with appropriate precautions taken during their use. Acids and solvents shall not be rinsed down the drain during cleaning but shall be collected for proper treatment and disposal.

5.3.3 Laboratory Animals. Federal regulations require that the Animal Care and Use Committee review and approve the use of animals in research. The Center for Comparative Medicine (CCM) administers all activities related to the care and use of animals.

Laboratory animals may be potential sources of hazardous chemical exposure from metabolic products, wastes, cage litter, and contaminated cages. The preparation of food and water containing toxic substances under investigation shall be done with all precautions ordinarily taken to protect the health and safety of personnel. The OSHA Laboratory Standard guidelines for animal work with chemicals of high chronic toxicity shall be followed. The guidelines cover administration of the toxic substance, aerosol suppression, personal protection, and waste disposal. Contact ORS for the text of the guidelines.

Another possible concern in handling laboratory animals is the potential for exposure to inherent biological hazards. Aside from the biological agents to which the animals are deliberately exposed, lab animals may harbor indigenous pathogens that can be transmitted to humans. This is of particular concern with nonhuman primates.

In the case of macaque monkeys, animal handlers may contract Cercopithecine herpesvirus ([CHV-1], commonly referred to as Herpesvirus simiae or "B-virus") infection that can be deadly. The virus is primarily transmitted through bites, scratches, or other contamination of broken skin; however, a fatality due to a splash of a macaque's body fluid in the eye has been reported. The high risk of infection places particular importance on the wearing of personal protective equipment to prevent exposure. Animal handlers working with macaques and other nonhuman primates shall always don appropriate gloves, surgical masks, splash goggles, and lab coats or other suitable covering that leaves no exposed skin or mucous membranes.

5.3.4 Relocating or Closing a Laboratory. Guidelines are available from ORS to assist you in safely relocating laboratory chemicals or biological agents within the University.

All chemicals that will not be relocated shall be listed on a Surplus Chemical Collection Form. The form shall be completed before the principal investigator relinquishes possession of the vacated laboratory. Disposition of all unwanted chemicals is the responsibility of the principal investigator. The department of record is responsible for the safe and lawful cleanup and disposition of all chemicals and biological materials that are abandoned. All biological materials shall be autoclaved or chemically disinfected and disposed of before the laboratory is vacated.

The principal investigator is responsible for ensuring that surfaces and equipment potentially contaminated with hazardous chemicals or biological agents are decontaminated before the laboratory is vacated. Accessible surfaces (chemical fume hoods, sinks, benchtops) should be cleaned, when practical, by the principal investigator and staff. If this is not possible, an outside contractor specializing in the testing and cleaning of contaminated laboratory equipment should be contacted. The principal investigator shall provide the contractor with thorough and accurate information pertaining to the past uses of the equipment.

To confirm that a vacated lab is properly emptied of hazardous materials, decontaminated, and ready for new occupants, the principal investigator or laboratory supervisor shall prepare the Laboratory Closeout Checklist. This form is available from ORS or on the Web and shall be signed by the respective department head (or designee). Should the principal investigator fail to complete the items required on the form, the department becomes financially and administratively responsible for the safe disposition of the hazardous materials and the decontamination of work surfaces.

ORS offers a laboratory survey to any principal investigator vacating a lab to assist in identifying the tasks that must be finished for clearance of the space. ORS will require a completed Laboratory Closeout Checklist when performing final services such as chemical waste removal for the lab.

5.3.5 Transportation of Hazardous Materials. A personal vehicle shall not be used to transport hazardous materials. The U.S. Department of Transportation (DOT) requires that a licensed hazardous materials transporter be employed if hazardous materials are transported on a public highway or by air or water. DOT also requires that all individuals offering a hazardous material for transport receive training. The material to be shipped shall be properly packaged in accordance with all applicable regulations and appropriate shipping papers shall be provided.

Biological materials shall be shipped in compliance with DOT and Centers for Disease Control and Prevention regulations. Transport of regulated plant or animal pathogens shall comply with U.S. Department of Agriculture and Illinois Department of Agriculture regulations.

5.3.6 Laboratory Doors. Fire and life safety codes as well as University policy require that laboratory doors be kept closed at all times. Keeping doors closed also helps ensure that ventilation systems work properly and maintain contaminant-containing pressure differentials between labs and corridors. This is especially important in newer buildings with sensitive energy conservation systems.

5.3.7 Visitors to Laboratories. Do not allow visitors, including children and pets, in laboratories where hazardous substances are stored or are in use or hazardous activities are in progress. Students from primary and secondary schools occasionally may enter laboratories as part of educational programs under carefully controlled and supervised conditions. Colleagues, prospective students, and others may be invited into laboratories for legitimate academic and research purposes. Each individual working in a laboratory should prudently evaluate the risks to visitors, especially to persons of increased risk such as children and immunosuppressed individuals. This may be especially important in facilities such as animal quarters.

5.4.1 Laboratory Ventilation. Laboratories shall be provided with general ventilation adequate for employee comfort and sufficient to supply air for chemical fume hoods and other local ventilation devices. Because the general air supply is not adequate for manipulating hazardous materials on an open lab bench, volatile or toxic chemicals shall be handled in a chemical fume hood or other appropriate containment device.

Laboratory ventilation shall change the air at least 10 times per hour, depending on the nature of the laboratory work. Except in special circumstances approved by ORS, air in laboratories shall be at a negative pressure with respect to the rest of the building. Air diffusers or grilles shall be so designed and located as to direct the air over the laboratory personnel and sweep the contaminated air away from their breathing zone. To promote uniform distribution and mixing of air in large laboratories, the supply registers shall deliver the air in all directions, at a typical velocity of 20 linear feet per minute.

Problems with general ventilation shall be reported promptly to Facilities Management. Adjustments or alterations to the general ventilation equipment of a laboratory shall be performed only under the supervision of Facilities Management.

On occasion, Facilities Management will issue notices of intent to perform maintenance work on the ventilation system. These notices shall be heeded and chemical fume hoods shall not be used when Facilities Management is involved in repairing or adjusting the ventilation system. The supervisor of the laboratory is responsible for ensuring that the Facilities Management crew is informed of the hazards in the area. The chemical fume hood shall be cleared of toxic materials and properly decontaminated before the work begins. Facilities Management will likely request ORS to inspect the chemical fume hood prior to maintenance or repair work. Be prepared to supply a detailed history of chemical and biological agent use in the chemical fume hood for safety evaluation purposes.

5.4.2 Chemical Fume Hoods. A chemical fume hood is an important engineering control for preventing exposure to hazardous materials. In conjunction with sound laboratory techniques, a chemical fume hood serves as an effective means for capturing toxic, carcinogenic, offensive, or flammable vapors or other airborne contaminants that would otherwise enter the general laboratory atmosphere. With the sash lowered, the chemical fume hood also forms a physical barrier to protect workers from hazards such as chemical splashes or sprays, fires, and minor explosions. Chemical fume hoods may also provide effective containment for accidental spills of chemicals, although this is not their primary purpose.

Many University chemical fume hood controllers are equipped with emergency purge buttons. These should be activated during an incident or if the design of an experiment fails. The button will temporarily increase total exhaust flow from the lab and help remove toxic vapors or dusts from the entire space. The deliberate release and venting of chemicals (i.e., evaporation) in chemical fume hoods shall never be used as a means of disposal.

Turbulence is the greatest enemy to proper chemical fume hood operation. It can lead to backspill of contaminants out of the chemical fume hood. The operator has significant control over the factors that cause turbulence and, consequently, the chemical fume hood's capture efficiency.

For example, chemical fume hoods are not meant for storage of chemicals. Storing chemical containers and equipment in a chemical fume hood impairs its performance. The containers and equipment create turbulence as airflow is diverted around them. Volatile and odorous chemicals and highly toxic gases shall be stored in ventilated cabinets.

If chemical containers or bulky devices must be maintained in the chemical fume hood during an experiment, they should be elevated two to three inches above the interior work surface using jacks, apparatus scaffolding, support stands, ring stands, metal bars or stilts, etc. Materials remaining directly on the work surface block the incoming air and propel it back toward the chemical fume hood face. The elevation of materials in the chemical fume hood allows air to pass unimpeded to the bottom exhaust opening at the chemical fume hood's back wall.

Turbulence is also created at the face of the chemical fume hood when obstacles to airflow such as containers and equipment are too close to the sash. Containers and equipment should always be moved six inches back from the inner edge of the air sill. This practice can reduce vapor concentrations at the chemical fume hood face by about 90 percent.

Even the movement of one's hands can interrupt airflow patterns and disturb proper circulation of exhaust air. When reaching into the chemical fume hood, take care to move your hands slowly with smooth gestures and no jerking. If working at a chemical fume hood with a horizontal sash, use one of the panes as a barrier to splashes. Position the pane directly in front of you and move your hands on opposite sides of the pane.

Apparatus in chemical fume hoods shall be fitted with traps, condensers, or scrubbers to remove toxic fumes, gases, vapors, or dusts before venting to the atmosphere. Chemical fume hood performance is also dependent on the room's air flow pattern, including airflow generated by drafts and persons walking by. Minimize traffic and opening and closing of doors near the chemical fume hood. When the chemical fume hood is in use, the sashes should be pulled down as far as workable for minimal external airflow interference and maximum barrier protection.

Chemical fume hoods used for hazardous chemicals shall have an average face velocity of 80 to 100 feet per minute at a minimum sash height of twelve inches. Face velocity shall not exceed 120 fpm at the working sash height.

Compounds such as perchloric acid or aqua regia are likely to cause chemical fume hood corrosion. Please refer to Section 6.7 for further information with respect to perchloric acid.

Chemical fume hoods shall be evaluated for performance upon installation and following any alterations. ORS monitors chemical fume hoods annually. The fans and duct systems are maintained and inspected by Facilities Management. Any problems with hood ventilation or air flow should be reported to ORS or Facilities Management for inspection and evaluation.

Refer to The Chemical Fume Hood Handbook for further information regarding optimum hood operation and an understanding of ventilation principles.

5.4.3 Safety Showers. Safety showers shall be installed in all areas where employees may be exposed to splashes or spills of materials that may be injurious to the eyes and body. As a general rule, new shower installations shall adhere to the recommendations for shower location and minimum performance requirements established in American National Standard Z-358.1 (1998). Showers shall be placed as close to the hazard as possible, but in no case more than 10 seconds' travel time from the hazard. Department heads shall ensure that safety showers are installed in the department where needed.

Every laboratory employee shall be instructed in the location(s) and use of a safety shower. Ideally, a person should be able to find the shower with his or her eyes closed. Safety showers shall provide a minimum of 20 gallons of water per minute and deliver the volume at low velocity; a high-velocity shower could further damage injured tissue.

Ideally, the water temperature of the shower should be tepid to prevent pain or shock to a person standing under it for 15 minutes. Safety showers shall have quick-opening valves requiring manual closing so that a person does not have to hold the valve open while trying to undress or wash off. The pull handle shall be a delta bar or large ring within easy reach but not so low as to be in the way.

Because not all laboratories have safety showers, a "Safety Shower" sign shall be placed outside each room that has a shower. Flammable-liquid cabinets or other hazardous equipment or material shall not be placed near a safety shower, and access to the shower or the activating handle shall not be impeded. The floor shall be clear in a 34-inch-diameter area under the shower.

Safety showers shall be tested and inspected at least annually. Inspection includes a visual check of visible plumbing and verification of proper operation. Facilities Management conducts the annual tests and maintains related records. Contact Facilities Management to schedule safety-shower testing if the shower you intend to use in an emergency has not been tested in the last 12 months.

5.4.4 Eyewash Fountain. An eyewash providing a continuous, low-pressure stream of aerated water shall be provided in each laboratory in which chemical or biological agents are used or stored and in laboratories where nonhuman primates are handled. The eyewash shall be easily accessible from any part of the laboratory. If possible, the eyewash should be located near the safety shower so that, if necessary, the eyes can be washed while the body is showered.

New eyewash installations shall adhere to the recommendations for minimum performance requirements established in American National Standard Z-358.1 (1998). Eyewash fountains shall supply 0.4 gallons of water per minute for 15 minutes. The three basic kinds of eyewash fountains are the fixed-base shower, much like a drinking fountain, with arm or foot-pedal operation, faucet-mounted units, and the handheld-hose type, with aerating nozzle(s) and lever-operated valve. The main criteria are that, whichever eyewash chosen:

• it shall activate within one second
• it shall provide hands-free continuous operation once activated
• the flushing streams shall rise to approximately equal heights and the flushing fluid will wash both eyes simultaneously.

Contact ORS for information on the types of eyewashes available.

Gravity-feed eyewash devices (wall-mounted or on mobile carts) are not recommended unless they provide adequate water supply for 15 minutes of eye washing and the stored water is treated so that it does not become microbially contaminated. For such units, a documented monthly maintenance program shall be established to ensure that the water supply remains in satisfactory and usable condition. Bottle-type portable eyewashes are not acceptable, as they do not have the capacity to deliver 0.4 gallons of water per minute.

Principal investigators are responsible for ensuring that eyewash fountains in their labs are tested monthly to ensure that the valves operate properly, the required volume and aerated stream are available, and the pipes or hose are cleared of sediment that might collect.

5.4.5 First Aid Kits. Principal investigators are responsible for supplying at least one first aid kit for their lab groups. This kit shall not be shared between lab groups. The kit should be stored in the main lab and be easily accessible to any other lab locations that belong to a particular group. If the same group occupies labs that are not in immediate proximity (i.e., labs in different buildings or on different floors), a first aid kit shall be available for each set of adjacent labs. Each lab member shall be trained to know where the kit is located.

The first aid kit should contain the items recommended in the First Aid Kit Policy and Guidelines for Laboratories, available from ORS or on the Web. It shall be inspected monthly to ensure that no items are missing and that none of the remedies (e.g., saline solution, ointment) in the kit have expired. The inspections shall be documented (an inspection record is included in the policy).

The CBSC and ORS recommend CPR and first aid training for at least two lab members in each lab group. Such training can be arranged through the Red Cross or the Medical Education Division within the University Health Service.

5.4.6 Laboratory Sinks and Drain Traps. Every laboratory using chemical or biological agents shall have at least one sink, preferably located near the room exit, available for handwashing. The sink shall be cleaned regularly to eliminate contamination, and soap shall be supplied for handwashing. Antimicrobial soaps are not necessary. They tend to dry the user's skin by stripping natural oils.

Drain traps in sinks, floors, and other places will dry out if they are not used regularly, allowing odors and contamination to back up into the room. Drain traps shall be kept filled with water to prevent backup. Also fill cup sinks on benches and in chemical fume hoods.

5.4.7 Electrical Equipment. Electrical currents of very low amperage and voltage may result in fatal shock under certain circumstances. Voltages as low as 24 volts AC can be dangerous and present a lethal threat. Low-voltage DC circuits do not normally present a hazard to human life, although severe burns are possible. The duration of contact with a live circuit affects the degree of damage, especially with regard to burns.

All electrical switches shall be labeled, including circuit breakers in the service panels, and all laboratory personnel shall know where these controls are and how to shut off circuits or equipment in case of fire or other accident. Any electrical equipment that is not operating properly or seems to be overheating shall be turned off immediately and inspected by a qualified technician.

Electrical equipment should be inspected periodically to confirm that the cords and plugs are in safe condition. Circuit diagrams, operating instructions, descriptions of hazards, and safety devices are usually provided by the manufacturer and should be kept on file for reference.

Only three-wire grounded, double insulated, or isolated wiring and equipment shall be used in 110V-115V AC applications. All wiring and equipment shall comply with the National Electrical Code. In specifically designated laboratories, cold rooms, or storage rooms or other locations where concentrations of flammable vapor-air mixtures are likely to occur, certified explosion-proof wiring and equipment, including light fixtures, switches, refrigerators, and telephones, shall be used. If you have any questions with regard to the code, contact the Office of Risk Management for guidance at 1-3253.

Series-wound motors with carbon brushes, typically found in household appliances such as blenders and mixers, are not spark-free and shall not be used in laboratories where flammable vapors accumulate. Equipment manufactured for use in laboratories generally contains induction motors.

Electrical extension cords should be avoided, where practical, by installing additional electrical outlets. Only electricians from Facilities Management are permitted to make electrical modifications in University properties. When extension cords are used, the wire gauge shall be equal to or larger than the size of the cord being supplied by them. Electrical cords on equipment shall be discarded or repaired if frayed or damaged. Cords should be kept as short as practical to avoid tripping hazards and tangles.

Place electrical equipment so as to minimize the possibility that water or chemicals could spill on it or that water could condense and enter the motor or controls. In particular, place such equipment away from safety showers. In cold rooms, condensation can be minimized by mounting electrical equipment on walls or vertical panels.

Only qualified individuals are permitted to make electrical repairs to any kind of electrical equipment. All electrical equipment shall be deenergized and tagged or locked out according to OSHA requirements before repairs are made. If adjustments or other contact are to be made with energized electrical equipment, a second person shall be present. Be sure you are not on a damp surface or touching a potential grounding surface. Use insulated tools, keep your hands dry, and wear safety glasses to prevent injury from sparks.

If a worker receives an electrical shock and is in contact with the energized device, use nonconductive gloves or a nonconducting device to pull or push the victim free from the electrical source. Help victims only if you are certain that you will not endanger your own safety. Turn off or disconnect the power source if possible. Call 911. If a trained person is available, start CPR if necessary. Get medical assistance at once.

5.4.8 Static Electricity. Static electricity may be generated whenever two surfaces are in contact with one another. Examples are processes such as evaporation, agitation, pumping, pouring of liquids, or grinding of solids or powders. Equipment used in these operations shall be bonded and grounded to prevent static charges from accumulating on the containers. Blanketing with inert gas may also prevent sparks in equipment where flammable vapors are present. Static electricity is increased by low absolute humidity, as is likely in cold weather. Some common potential sources of electrostatic discharges are ungrounded metal tanks and containers; metal-based clamps, nipples, or wire used with nonconducting hoses; high-pressure gas cylinders upon discharge; and clothing or containers made of plastic or synthetic materials.

5.4.9 Centrifuges. If a tabletop centrifuge is used, make certain that it is securely anchored in a location where its vibration will not cause bottles or equipment to fall. Ensure that the disconnect switch is working properly and shuts off the equipment when the top is opened. Centrifuge rotors shall be balanced each time they are used. Securely anchor and shield each unit against flying rotors. Regularly clean rotors and buckets with noncorrosive cleaning solutions.

Always close the centrifuge lid during operation, and do not leave the centrifuge until full operating speed is attained and the machine appears to be running safely without vibration. Stop the centrifuge immediately and check the load balances if vibration occurs. Check swing-out buckets for clearance and support.

5.4.10 Vacuum Pumps. If vacuum pumps are used with volatile substances, the input line to the pump shall be fitted with a cold trap to minimize the amount of volatiles that enter the pump and dissolve in the pump oil. The exhaust from evacuation of volatile, toxic, or corrosive materials shall be vented to an air exhaust system. A scrubber or trap may also be required.

If pump oil becomes contaminated with toxic chemicals, it will exhaust the chemicals into the room air during future use. Pump oil shall be changed if it becomes contaminated. Dispose of used pump oil with ORS.

Before using the vacuum pump, ensure that the moving parts have been properly guarded and that there are no exposed points of operation (i.e., exposed belt) that could nip a finger or catch hair or clothing. Wear eye protection when working with a vacuum pump or setting up the cold trap assembly.

5.4.11 Drying Ovens and Furnaces. Volatile organics shall not be dried in ovens that vent to the room air. Glassware rinsed with organics should not be oven dried unless it is first rerinsed with water. Bimetallic strip thermometers rather than mercury thermometers are recommended for measuring oven temperatures. If a mercury thermometer breaks in an oven, the oven shall be turned off and cooled before cleanup is attempted. See Section 6.0 for information regarding cleanup of mercury spills, or contact ORS.

Wear heat-resistant gloves and appropriate eye protection when working at ovens or furnaces. ANSI-approved eyewear (i.e., heat-absorbing, reflective goggles) offers protection against projectiles and infrared radiation.

5.4.12 Syringes and Scalpel Blades. Syringes used with hazardous agents shall have needle-locking or equivalent tips to assure that the needles cannot separate during use. Disposal of needles and syringes contaminated with infectious agents is described in Section 7.0. Do not recap needles after use. Recapping of needles potentially contaminated with human blood, blood products, or other potentially infectious materials is prohibited.

Syringes, needles, or scalpels shall be disposed of immediately after use in sealable, puncture-resistant, disposable containers that are leakproof on the sides and bottom. The containers shall be appropriately labeled as to the chemical or biological hazard. Sharps containers shall be easily accessible to personnel in the immediate area of use.

5.4.13 Facility Cleaning and Maintenance. A custodial service has been contracted to wet-mop floors (including laboratory space) on a weekly basis. However, building services and custodial staff are prohibited from cleaning up chemical and biological materials (including spills), and custodians shall not be expected to mop any floors that have not been properly decontaminated after a spill.

In preparation for the cleaning service, the laboratory staff shall remove hazards that the custodians might encounter during their activities. Chemical containers on the floor and all containers of biohazardous waste shall be moved by laboratory occupants to a safe and secure location before custodians enter the lab. In the event that a supervisor does not wish a particular laboratory to be disturbed, custodial floor cleaning can be suspended on request of the area occupants. To have the mopping discontinued, contact Facilities Management and post a sign on the lab.

Likewise, if maintenance is required on any component of the laboratory, such as a sink or piece of equipment, the same principles of preparation apply. The supervisor shall ensure that the immediate area is decontaminated and any infectious agents or chemicals are removed to another secure area prior to initiation of work. The laboratory supervisor shall inform maintenance personnel of the presence of any hazardous materials to which they might become exposed.

Cleaning duties that are the specific responsibility of laboratory personnel shall be conducted on a regular basis to prevent accidental contact with hazards and to reduce clutter in the lab space. Laboratory equipment, including refrigerators, freezers, and work surfaces, shall be cleaned by laboratory staff. In laboratories using large amounts of powdered carcinogens, reproductive toxins, or acutely toxic materials, lab workers should avoid dry mopping or sweeping with a broom if this could cause the materials to become airborne.

Facility maintenance and custodial staff shall not handle or remove hazardous waste bags or other containers.

5.4.14 Glassware. Borosilicate glassware, such as Pyrex 7740, is the type preferred for laboratory experimentation, except in special experiments involving ultraviolet or other light sources or hydrofluoric acid, for which polypropylene containers are most appropriate. Measuring glassware, stirring rods, tubing, and reagent bottles may be ordinary soft glass. Vacuum or suction flasks shall be designed with heavy walls. Dewar flasks and large vacuum vessels shall be taped or otherwise screened or contained in metal to prevent glass from flying if they should implode. An ordinary thin-walled thermos bottle is not an acceptable replacement for a Dewar flask.

Because it can be damaged in shipping, handling, or storage, inspect glassware carefully before using it to be sure it does not have hairline cracks or chips. Even the smallest flaw renders glassware unacceptable and possibly dangerous. Flawed glassware shall be discarded in a rigid, puncture-resistant broken-glass bin. Where the integrity of glassware is especially important, it can be examined in polarized light for strains.

5.4.15 Assembling Apparatus. Operations that may generate airborne contaminants or that use flammable liquids or toxic, reactive, or odoriferous materials shall be conducted in a chemical fume hood or other appropriate containment enclosure. Whenever hazardous gases or fumes are likely to evolve, an appropriate trap, condenser, or scrubber shall be used to minimize release of material to the environment.

Apparatus should be set up well back from the edge of the work area, be it a bench or a hood. When assembled in a hood, apparatus should not obstruct the area. To avoid overflow, choose apparatus with at least 20 percent more capacity than would normally accommodate the volume of chemical planned for the operation. All parts of the apparatus shall be firmly balanced and supported. Tubing shall be fastened with wire or appropriate clamps.

Stirrer motors and vessels shall be positioned and secured to ensure proper alignment. Magnetic stirring is preferable, and nonsparking motors or air motors shall be used in any laboratory that might contain flammable vapors.

Funnels and other apparatus with stopcocks shall be firmly supported and oriented so that gravity will not loosen the stopcock plug. Use a retainer on the stopcock plug and lubricate glass stopcocks. Do not lubricate Teflon stopcocks.

Include a vent in apparatus for chemicals that are to be heated and place boiling stones in unstirred vessels. If a burner is to be used, distribute the heat with a ceramic-centered wire gauze. Insert a thermometer in heated liquids if dangerous exothermic decomposition is possible. This will provide a warning and may allow time to remove the heat and apply external cooling.

A pan under a reaction vessel or container will confine spilled liquids in the event of glass breakage.

If a hot plate is used, be sure that its temperature is less than the autoignition temperature of the chemicals likely to be released and that the temperature control device does not spark. Whenever possible, use controlled electrical heaters or steam in place of gas or alcohol burners.

5.4.16 Eliminating Mercury Thermometers. Metallic mercury is highly toxic by skin absorption, inhalation, and ingestion. Lab workers face limited potential exposure whenever they break mercury-filled thermometers. The mercury contamination may infiltrate cracks in benches and the floor or spread beneath equipment and instruments. The contamination is insidious and difficult to remove completely. The difficulty is magnified if the thermometer breaks in a water bath or sink.

One of the best methods for eliminating this hazard and metallic mercury in labs is to replace all mercury thermometers with nonmercury instruments. Alternatives to mercury thermometers are spirit-filled or digital units. ORS strongly urges you to substitute nonmercury thermometers whenever possible.

5.4.17 Fire Extinguisher Policy. Fire extinguishers are provided by the University in corridors, public areas, laboratories, and other locations where required by building and life safety code. Facilities Management provides fire extinguishers in new and renovated laboratories during the construction phase. All existing labs were equipped with extinguishers previously. Missing extinguishers should be reported to Facilities Management. Extinguishers in individual labs are ordered through Facilities Management at no cost to the principal investigator. Call 1-5201 to issue a work order for installation. Facilities Management will inspect and maintain all fire extinguishers, both inside and outside laboratories.

5.4.18 Special Precautions Against Ultraviolet Light. Germicidal lamps using ultraviolet light are common fixtures in biological safety cabinets, where they serve to destroy bacteria and molds. These lamps are considered a high-level source of UV radiation; exposure to the lamps without adequate personal protection could result in skin or eye injury.

Acute skin effects due to direct UV exposure vary with dose. Dermal effects include three types: erythema (sunburn), increase in pigmentation (suntanning), and hyperplasia (increase in epidermal cell growth, resulting in enlargement of tissue). UV radiation may also increase the cutaneous effects of certain solvents and photosensitizing chemicals.

Eye injuries attributable to UV exposure are most prevalent among welders. Laboratory applications are unlikely to achieve doses comparable to those in industrial settings, but a small amount of UV light may produce temporary eye injury, such as corneal inflammation and "sand-in-the-eye" sensation.

A great concern with UV eye exposure is that the victim is often unaware that damage is occurring. Usually, no pain develops from the eye injury until four to six hours after the exposure. The only way to prevent injury is to minimize eye exposure to UV light.

Appropriate protection against UV exposure includes long sleeves and laboratory gloves. For individuals particularly sensitive to UV light, suntan lotion on the exposed skin of the face is recommended. ANSI-approved shaded eye protection with side enclosures shall be worn in the vicinity of a UV light fixture not shielded by a physical barrier.

5.5 Signs and Labels for Laboratories
The following signs and labels are required for all laboratories in University facilities:

• An "Emergency Information" sign shall be posted outside all laboratories, either on the outside of the door or on the wall beside the door. This sign provides information on specific hazards in the laboratory, special precautions, personal protective equipment, and telephone numbers of responsible faculty and staff. The information provided on these signs, as with all other signs, shall be updated as necessary.
• A green-bordered "Emergency Procedures for Laboratories" sign shall be posted in a prominent location inside the laboratory, near the door or telephone. This sign briefly describes what to do in case of an emergency.
• A label bearing the University Police emergency number shall be placed on each telephone in the laboratory.

ORS will advise principal investigators and laboratory supervisors who require additional signs and labels.

Principal investigators shall ensure that laboratory personnel are properly trained and shall certify training on the Laboratory Safety Profile. An agenda of required training for employees and students (including summer and work-study students) who handle hazardous chemicals appears in the Hazard Communication Program. Bloodborne pathogens training information may be found in the Bloodborne Pathogens Program.

Training materials to assist the principal investigator or department head are available from ORS. In addition, ORS can provide general safety seminars for laboratory or department groups. ORS training is general in nature; principal investigators are required to provide specific safety training in the particular hazards of their laboratories.

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