Each laboratory must identify which hazardous chemicals will be encountered by its workers. All containers for chemicals must be clearly labeled. The employer must ensure that workers do not use, store, or allow any other person to use or store, any hazardous substance in the laboratory if the container does not meet the labeling requirements outlined in the Hazard Communication Standard. Labels on chemical containers must not be removed or defaced.
Safety Data Sheets (SDSs) for chemicals received by the laboratory must be supplied by the manufacturer, distributor, or importer and must be maintained and readily accessible to laboratory workers. SDSs are written or printed materials concerning a hazardous chemical. Employers must have a SDS in the workplace for each hazardous chemical in use.
The United States is participating in the Global Harmonization System of Classifying and Labeling Chemicals (GHS) process and has adopted the GHS in its HazCom 2012 standard (29 CFR 1910.1200).
The GHS is a system that defines and classifies the hazards of chemical products, and communicates health and safety information on labels and Safety Data Sheets.
As we mentioned earlier, each laboratory should develop a Chemical Hygiene Plan, or CHP. The purpose of the CHP is to provide guidelines for prudent practices and procedures for the use of chemicals in the laboratory. The Laboratory standard requires that the CHP set forth procedures, equipment, PPE and work practices capable of protecting workers from the health hazards presented by chemicals used in the laboratory. See a sample CHP and more information on CHP elements.
OSHA’s Air Contaminants standard (29 CFR 1910.1000) provides rules for protecting workers from airborne exposure to more than 400 chemicals. Several of these chemicals are commonly used in laboratories and include: toluene, xylene, and acrylamide.
Toluene and xylene are solvents used to fix tissue specimens and rinse stains. They are primarily found in histology, hematology, microbiology and cytology laboratories.
The amount of toluene that a worker breathes over a work day is determined by the concentration in the air, and the length of time the worker is in that atmosphere. Recommendations for exposure limits have been made by the National Institute for Occupational Safety and Health (NIOSH) and the American Conference of Governmental Industrial Hygienists. The Hazard Communication Standard requires that the Threshold Limit Value (TLV) be disclosed on a safety data sheet.
The Environmental Protection Agency reports that commercial or mixed xylene usually contains about 40-65% m-xylene and up to 20% each of o-xylene and p-xylene and ethylbenzene. Xylenes are released into the atmosphere as fugitive emissions from industrial sources, from auto exhaust, and through volatilization from their use as solvents.
Acute (short-term) inhalation exposure to mixed xylenes in humans results in irritation of the eyes, nose, and throat, gastrointestinal effects, eye irritation, and neurological effects. Chronic (long-term) inhalation exposure of humans to mixed xylenes results primarily in central nervous system (CNS) effects, such as headache, dizziness, fatigue, tremors, and lack of coordination; respiratory, cardiovascular, and kidney effects have also been reported.
Acrylamide is usually found in research laboratories and is used to make polyacrylamide gels for separations of macromolecules (e.g., DNA, proteins).
The International Agency for Research on Cancer (IARC) has classified acrylamide as a possible human carcinogen (Group 2B); the American Conference of Governmental Industrial Hygienists (ACGIH) lists acrylamide as a suspected human carcinogen.
To prevent worker exposure, employers must implement a written program for chemicals that workers are exposed to and that meet the requirements of the Hazard Communication standard. This program must contain provisions for worker training, warning labels and access to Safety Data Sheets (SDSs).
For more information on Acrylamide, see the Agency for Toxic Substances & Disease Registry.
Formaldehyde is used as a fixative and is commonly found in most laboratories. The employer must ensure that no worker is exposed to an airborne concentration of formaldehyde which exceeds 0.75 parts formaldehyde per million parts of air (0.75 ppm) as an 8-hour time weighted average (TWA), see 29 CFR 1910.1048(c)(1).
The Hazard Communication Standard requires employers to maintain a SDS, which manufacturers or distributors of formaldehyde are required to provide. The SDS must be kept in an area that is accessible to workers that may be exposed to formaldehyde.
Employers must provide the following to workers to prevent exposure:
One of the most common chemicals that laboratory workers are exposed to is latex, a plant protein. The most common cause of latex allergy is direct contact with latex, a natural plant derivative used in making certain disposable gloves and other products. Some healthcare workers have been determined to be latex sensitive, with reactions ranging from localized dermatitis (skin irritation) to immediate, possibly life-threatening reactions. Under OSHA’s Personal Protective Equipment Standard (29 CFR 1910.132), the employer must ensure appropriate personal protective equipment (PPE) is accessible at the worksite or issued to workers.
Latex-free gloves, glove liners, powder-free gloves, or other similar alternatives are obtainable and must be readily accessible to those workers who are allergic to latex gloves or other latex-containing PPE.
Latex allergy should be suspected in workers who develop certain symptoms after latex exposure, including:
An exposed worker who exhibits these symptoms should be evaluated by a physician or other licensed healthcare professional because further exposure could cause a serious allergic reaction.
Once a worker becomes allergic to latex, special precautions are needed to prevent exposures. Certain medications may reduce the allergic symptoms, but complete latex avoidance is the most effective approach.
Appropriate work practices should be used to reduce the chance of reactions to latex. If a worker must wear latex gloves, oil-based hand creams or lotions (which can cause glove deterioration) should not be used unless they have been shown to reduce latex-related problems and maintain glove barrier protection. After removing latex gloves, workers should wash their hands with a mild soap and dry them thoroughly.