The Basics of Laboratory Safety (Part II): What Should Be in Place?
To better ensure the safety and health of all those working in a laboratory, there are some basic rules to remember before starting work.
- Never tolerate practical jokes, running, and other forms of horseplay while working in a laboratory.
- Avoid startling or distracting other laboratory employees.
- Do not bring children, visitors, or pets into the laboratory.
- Laboratory equipment should only be used for its intended purpose.
- Employees should not work alone in the laboratory or chemical storage areas if using chemicals or performing a task that is considered hazardous.1
Practice good laboratory awareness:
- Know the location and correct use of safety and emergency equipment, such as emergency eyewash and shower, first-aid kit, and fire extinguisher.
- Know emergency response procedures and alarms.
- Know potential hazards and appropriate precautions for each task. Employees should be able to answer the following questions:
- What are the hazards?
- What could happen?
- What preparations are necessary?
- What precautions are needed to minimize the risk?2
- Be aware of what others working in the laboratory are doing, as well as what materials are being used and the associated exposures and necessary precautions.3
Good housekeeping practices are essential for maintaining a safe laboratory environment. Laboratories should be kept clean and well-organized. Pre-work planning can help ensure that work areas are uncluttered. After work is completed, time should be allotted for a thorough clean-up of the work area and equipment. Materials should not be stored on or above the work area counter tops or in fume hoods. All containers should be labeled to identify the contents if not in direct control of the laboratory employee. Unused equipment and materials should be properly stored or removed and not allowed to collect in the laboratory or block aisles and exits.
Laboratory floors should be kept dry. Spills of any material, chemicals or water should be addressed immediately and appropriately. Information regarding spill clean-up can usually be found on the material safety data sheet (MSDS). Chemical spill kits should be available and accessible.
Because many chemicals can be absorbed directly into the skin, it is important to keep exposed skin covered as much as possible while working in a laboratory. If contact with the skin does occur, wash quickly and thoroughly. An appropriate cleaning agent such as soap or neutralizing material should be readily available for the chemicals being used. Consult the MSDS for the proper cleaning agent and avoid solvents. Hand washing is important, especially before leaving the laboratory for any reason. If gloves are worn, it is a good practice to wash the hands with the gloves on first, and again after the gloves have been removed.
It is essential that appropriate and protective clothing be worn in a laboratory. Avoid wearing shorts and skirts; long sleeve shirts are preferable to short sleeve shirts. Loose-fitting or torn clothing, jewelry, and unrestrained hair should be avoided. Shoes must be worn at all times. Open-toed shoes, sandals, and shoes with cloth or woven uppers provide no protection and should not be worn in a laboratory. Boots or chemical-resistant overshoes may be worn when working with corrosives or other hazardous materials that may be absorbed into regular shoes.4
Laboratory aprons or coats should be worn over standard clothing to protect against contamination from splashes and spills. Both need to be chemical resistant and fire retardant. The MSDSs can be helpful in determining what clothing and other personal protective equipment should be used. Laboratory coats need to close with snaps, not buttons, so they are easy to remove. The coats should be kept completely snapped while in the laboratory. While working with corrosive materials, plastic or rubber aprons may be worn. Because coats or aprons may become contaminated, they should be removed whenever leaving the laboratory and never worn in restrooms or eating areas.5
Laboratory clothing must be kept clean. Launder laboratory clothing separately from other clothing to avoid cross-contamination. If contaminants cannot be adequately removed using appropriate decontamination procedures, the clothing must be properly discarded and replaced. Disposable suits, such as Tyvek®, may be preferred in some cases.6
There should be no eating, drinking, smoking, chewing gum, or application of cosmetics in the laboratory or chemical storage areas. Storage of food, drinks, gum, cosmetics, and tobacco products should also not be allowed in these areas, except for experimental purposes. These items can become contaminated, possibly causing a significant exposure if ingested or applied to the skin.7
Refrigerators and freezers intended for laboratories are designed to resist corrosion and reduce the chance of fire or explosion and should be used for experimental materials only. These units should be labeled to indicate the intended use, such as “For Laboratory Use Only-No Food or Beverages Allowed.” All items stored in laboratory refrigerators or freezers should be labeled with the contents, owner, and any potential hazards or precautions. Consumable food items kept in laboratory refrigerators and freezers should be labeled “For experimental purposes only” and not for consumption. Only chemicals should be stored in units specified for chemicals. Personal food items should be kept in a refrigerator that is not used for experimental materials and is away from the laboratory and chemical storage areas.8
Flammable materials that must be refrigerated should be kept in an Underwriters Laboratory (UL) listed or Factory Mutual (FM) approved explosion-proof refrigerator.9
Incompatible Materials – Storage and Labeling
Many chemicals, when mixed with other chemicals intentionally or accidentally, can cause a hazardous reaction, such as a toxic gas, fire, or explosion. For example, when ammonia is mixed with chlorine (bleach), harmful chloramine and hydrazine gases are produced. Add water and deadly chlorine gas is released. Incompatible materials should be stored separately. Never store chemicals in alphabetical order. This will result in many non-compatible chemicals being stored close together. The Chemical Reactivity Worksheet from the National Oceanic and Atmospheric Administration’s (NOAA) National Ocean Service Office of Response and Restoration includes a database of reactivity to help determine which chemicals are incompatible. Chemical container labeling should include reactivity information. Generally, liquids, compressed gases, and dry reagents should be stored separately by type and hazard class, such as acid, base, and oxidizer.10
Electrical Safety in a Laboratory
Death by electrocution, electrical shock, and burns are major injuries associated with electricity. These occur when the body becomes part of an energized electrical circuit. There are many types of electrical equipment used in laboratories, including, but not limited to, heating elements, pumps, lasers, and microwave ovens. Some devices used in laboratories, such as lasers, have capacitors that remain charged at potentially deadly levels even if the unit is disconnected from the power source.
It is critical that electrical equipment be used properly and maintained in good condition. Regular inspections and preventative maintenance can reduce the chance of electrical injuries from equipment.11
All electrical equipment used in a laboratory should be UL listed or FM approved, and be properly grounded. Pre-use inspections include checking the power cord for damage, such as broken insulation, loose plugs or wires, and internal breaks in the wires. Make sure the ground prong on the plug is in place and in working order. All covers and guards should be in position and switches in good condition. Avoid the use of extension cords and only use them in temporary or short-term situations.
Everyone working in the laboratory should know the location of the circuit breaker panels and shut-off switches for the electrical systems. Circuit breakers need to be clearly labeled with what area, equipment, and circuit they serve, as well as if it is on, off, or tripped. Any equipment used near a sink or other wet location should be on a circuit protected by a ground fault circuit interrupter (GFCI). GFCIs should be tested at least monthly to ensure proper operation and replaced immediately if they fail.12
There are numerous hazards in a laboratory environment. Safety equipment used in laboratories help control these hazards and limit the risk of serious injury.
Chemical Fume Hoods
Chemical fume hoods are among the most important safety devices used in laboratories. Fume hoods are an exhaust ventilation system intended to draw potentially hazardous chemical fumes, vapors, and other contaminants away from the employee and prevent their release into the laboratory. Air is drawn from the laboratory, past the employee through an open sash, captured by openings in the top and rear of the cabinet and vented to a remote area, usually a roof top.13
Employees should be trained in the proper use and limitations of the hoods they will be using. The following are some important points for the safe and proper use of fume hoods:
- Fume hoods are not meant to be used for storage, unless designed and designated for this purpose (do not conduct experiments in hoods used for storage).
- All chemical and waste containers should be kept capped or covered.
- Never block the airflow. Do not place items in front of the vents/baffles. Airflow into the hood is affected by the air flow in the laboratory. Make sure it is adequate.14
- Regular inspections, testing, and maintenance are essential to ensure that fume hoods will operate properly and provide adequate protection for employees. Airflow should be checked and noted on a survey sticker placed on the unit. This certification check should be completed at least annually and any time the hood or the exhaust duct system has been modified.15
- Before using the hood, check the airflow rating on the survey sticker and compare to the airflow gauge. If significantly different, the hood may not be operating properly and needs to be taken out of service until checked, repaired, and recertified. Airflow on older units can be checked by holding a small piece of paper at the bottom of the sash.
- There should be emergency procedures in case of ventilation failure.
- The sash should be closed when not in use.16
Emergency Eyewashes and Showers
Laboratory employees may be exposed to different hazardous chemicals, many of which can cause a severe injury in the event of contact with the eyes or skin. Material safety data sheets often call for flushing the eyes or drenching the body with potable water for a period of time, usually a minimum of 15 minutes. For this purpose, laboratory employees should have easy access to an emergency eyewash and shower.
For additional information related to emergency eyewashes and showers, refer to the Workers’ Compensation Services – Loss Control (WCS-LC) web article titled, “Emergency Eyewash and Shower Safety” (December 2005).
Fire extinguishers are designed to put out small fires and should only be used by trained personnel to put out fires no larger than an office-size trash can. If the fire is larger, then it is best to activate the fire alarm and evacuate the building. Some agencies may direct their employees to not fight any fire and to evacuate instead.
Extinguishers are classified according to fire type:
- TYPE A — Combustibles – wood, cloth, paper, rubber and plastics
- TYPE B — Flammable Liquids – oil, grease and paint thinners
- TYPE C — Energized Electrical Equipment – electrophoresis
- TYPE D — Combustible Metals – magnesium, titanium, sodium, lithium, potassium
Multipurpose extinguishers are usually recommended because they are effective against Types A, B, and C fires.17
Extinguishers should be easily visible and accessible (not blocked) and securely mounted on a wall near an exit. All extinguishers should be checked in-house at least monthly for broken seals, damage, low gauge pressure, or improper mounting, and inspected by a qualified contractor a minimum of every 12 months. These inspections need to be documented, preferably on a tag attached to the unit. Units should be replaced or recharged if they have been used, damaged, not fully charged, or discharged.18
Flammable Material Storage Cabinets
Flammables and corrosives should be stored in minimal quantities in cabinets specifically designed for these purposes and built in accordance with 29 Code of Federal Regulation (CFR) 1910.106(d)(3)-Design, construction, and capacity of storage cabinets and National Fire Protection Association (NFPA) 30-Flammable and Combustible Liquids Code (2003).19 Refer to the cabinet manufacturer’s specifications for the types and maximum quantities that can be stored in the cabinet. Never store items in alphabetical order and do not put incompatible materials in the same cabinet. Vent plugs on flammable materials cabinets should remain in place to prevent supplying an oxygen source. These cabinets should be labeled “Flammable-Keep Fire Away.” Do not store paper products and other such combustible materials inside the cabinet and the top should not be used for storage of any kind.20
First aid kits
First aid kits should be used only to treat minor injuries, such as minor burns and cuts. Anything more severe should be addressed by a trained emergency responder. Laboratory kits should be located in an obvious and easily accessible place and should:
- Be kept in sanitary condition,
- Be limited to basic supplies such as Band-aids®, sterile gauze pads, bandages, scissors, antiseptic (spray, wipes or ointments),
- Include the following personal protective equipment:
- At least one pair of large size examination or laboratory gloves
- An airway resuscitator, such as the “pocket mask”, for use in mouth-to-mouth resuscitation
- A spill kit containing an appropriate disinfectant and other cleanup and disposal materials for handling spills of blood, vomit, or other body fluids.21
First aid kits should be monitored and maintained by a designated person and a log/tag attached for recording the inspection dates and inspector.22
Periodic laboratory inspections should be conducted using a checklist designed to review compliance with required policies, procedures, and safeguards, as well as physically confirming the condition and effectiveness of safety equipment. It is also important to make sure that the employee safety and hazard control provisions of the chemical hygiene plan are being followed by laboratory employees. Inspection checklists should include at least the following items:
- General laboratory safety
- Housekeeping (cleanliness, organization, clear aisles)
- Personal Hygiene (clothing, food storage, and eating)
- Chemical safety
- Safe chemical storage
- Separation of incompatible materials
- Proper use and condition of storage cabinets (flammables, corrosives, and other hazardous materials)
- Inventory, labeling, and quantity limitations
- Hazard communication (MSDSs, labeling)
- Safety equipment
- Chemical fume hoods
- Emergency eyewashes and showers
- Fire extinguishers
- First aid kits
- Electrical equipment
- Power cords in good condition
- Ground plugs in place and operable
Specific hazards in laboratories will vary depending on the type of laboratory and the materials used, so the contents of laboratory safety programs and inspections will vary. It is important to consider all hazards that could result in an injury or other catastrophic event and find ways to eliminate or control them.
1 Princeton University. “Laboratory Safety Manual.” Retrieved January 22, 2007 from, http://web.princeton.edu
3 University of Virginia, Office of Environmental Health and Safety. “Laboratory Survival Manual.” Retrieved January 22, 2007 from, http://keats.admin.virginia.edu
4 Princeton University. “Laboratory Safety Manual.” Retrieved January 22, 2007 from, http://web.princeton.edu
5 Oklahoma State University. “Laboratory Safety Manual.” Retrieved December 28, 2006 from, http://www.pp.okstate.edu
6 University of Virginia, Office of Environmental Health and Safety. “Laboratory Survival Manual.” Retrieved January 22, 2007 from, http://keats.admin.virginia.edu
7 Princeton University. “Laboratory Safety Manual.” Retrieved January 22, 2007 from, http://web.princeton.edu
9 Oklahoma State University. “Laboratory Safety Manual.” Retrieved December 28, 2006 from, http://www.pp.okstate.edu
10 Princeton University. “Laboratory Safety Manual.” Retrieved January 22, 2007 from, http://web.princeton.edu
12 Oklahoma State University. “Laboratory Safety Manual.” Retrieved December 28, 2006 from, http://www.pp.okstate.edu
13 Interactive Learning Paradigms Incorporated. “Fume Hood.” Retrieved January 22, 2007 from, http://www.ilpi.com/msds/ref/fumehood.html
15 Stanford University. “Laboratory Fume Hoods-Performance Criteria and Certification Protocol.” Retrieved January 31, 2007 from, http://www.stanford.edu/dept/EHS/prod/researchlab/lab/Laboratory_Fume_Hoods.pdf
16 University of Virginia, Office of Environmental Health and Safety. “Laboratory Survival Manual.” Retrieved January 22, 2007 from, http://keats.admin.virginia.edu
20 Oklahoma State University. “Laboratory Safety Manual.” Retrieved December 28, 2006 from, http://www.pp.okstate.edu
21 Princeton University. “Laboratory Safety Manual.” Retrieved January 22, 2007 from, http://web.princeton.edu
22 Oklahoma State University. “Laboratory Safety Manual.” Retrieved December 28, 2006 from, http://www.pp.okstate.edu
Interactive Learning Paradigms Incorporated (12/2004). Fume Hood. Retrieved January 22, 2007 from, http://www.ilpi.com/msds/ref/fumehood.html
National Institute of Environmental Health Sciences (2/2004). Laboratory Hoods, Biological Safety Cabinets And Other Exhaust Systems http://www.niehs.nih.gov
Oklahoma State University (5/2005). Laboratory Safety Manual. Retrieved December 28, 2006 from, http://www.pp.okstate.edu
Princeton University (1/2007). Laboratory Safety Manual. Retrieved January 22, 2007 from, http://web.princeton.edu
Stanford University (4/2003). Laboratory Fume Hoods-Performance Criteria and Certification Protocol. Retrieved January 31, 2007 from, http://www.stanford.edu/dept/EHS/prod/researchlab/lab/Laboratory_Fume_Hoods.pdf
University of Virginia, Office of Environmental Health and Safety (n.d.). Laboratory Survival Manual. Retrieved January 22, 2007 from, http://keats.admin.virginia.edu
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