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Formaldehyde (FAH) is a colorless, flammable gas with a strong, pungent odor. It is widely used in hospitals, in disinfectants, in carpet and furniture glues, and in a large number of other products. FAH is used in liquid form as a water and methanol solution called Formalin, which has a clear to milky appearance, and in solid form as a white powder called Para-formaldehyde. Formaldehyde gas may be given off by either liquid Formalin or Paraformaldehyde powder.

Formaldehyde's odor may be detected by some people. Many others, however, may not be able to smell it at all. Therefore, the sense of smell can not be relied upon to warn workers. Rather, irritation of the eyes, nose and bronchial tubes and watering eyes may indicate exposure to FAH or formaldehyde-containing substances more often than the sense of smell.


Formaldehyde products have a wide variety of uses in hospitals including:

  • tissue preservatives and in embalming fluids in autopsy rooms and the pathology department;
  • in kidney dialysis units and central supply as a sterilizing agent;
  • in operating rooms as a disinfectant.

Many detergents, disinfectants and cleaning agents used by custodians may contain FAH. It is very important for custodial and housekeeping workers to become familiar with the products they use, how to work with those products safely and when safer substitutes may be available. Read the label. Ask questions. And be careful when handling any product containing formaldehyde.

Formaldehyde is also used in carpet and furniture glues and can contaminate office air, especially where there is already a building ventilation problem. (See the AFSCME Fact Sheet on Indoor Air Pollution.)

Formaldehyde is also a byproduct of engine exhaust, photochemical smog, and incinerator and cigarette smoke.

Acute (Short-term, Immediate) Effects

  • Low Exposure Levels (0.1-5 parts per million): Burning, tearing of eyes; skin irritation.
  • Moderate Exposure Levels (10-20 ppm): Burning of eyes, nose and trachea; severe coughing; severe difficulty in breathing; and intense tearing of the eyes.
  • High Exposure Levels (50-100 ppm): Tightening in the chest; irregular heartbeat; severe headache; pulmonary edema (fluid in the lungs); inflammation of the lungs; possibly even death.

Chronic (Long-term, Delayed) Effects

  • "Sensitization": Some workers may be especially sensitive to formaldehyde and may develop an "allergic" reaction to very low-level exposures. This is called "sensitization" and can occur suddenly, even after an employee has worked with FAH for years with no reaction.

    Sensitization to formaldehyde may occur in other environments outside the hospital setting. Many office products such as glues used in office furniture and rugs, carbonless copy paper, and the inks used by some copy machines contain formaldehyde. Where ventilation is poor, exposure to formaldehyde in offices can lead to "Tight Building Syndrome," or "Indoor Air Pollution," where workers develop allergies and flu-like symptoms. (See the AFSCME Fact Sheet on Indoor Air Pollution.)

    Where facilities have in-house print shops to publish newsletters, menus, and other materials, employees must also expect to find products which contain formaldehyde and may present a health risk.

  • Eczema: Workers exposed to formaldehyde solutions or resins can develop eczema (flaking and itching skin), which may involve the eyelids, neck, hands, arms, armpits and scrotum. The condition may also be caused by contact with clothing contaminated with formaldehyde.
  • Dermatitis: Contact with formaldehyde or contaminated clothing can also cause a severe form of skin disease called "dermatitis." Dermatitis may range from simple reddening of the skin to severe cracking and blistering. Prolonged exposure may cause the fingernails to turn soft and brown-colored.
  • Eye Damage: Direct contact with the eye will cause severe burning and tearing, and may damage the cornea.
  • Cancer: Formaldehyde is known to cause nasal cancer and may be associated with other respiratory cancers and cancer of the brain. The National Institute for Occupational Safety and Health (NIOSH) has recommended that FAH be treated as a potential human carcinogen. The American Conference of Governmental Industrial Hygienists (ACGIH) also calls formaldehyde a suspected human carcinogen.
  • Reproductive System: There is also evidence that women workers exposed to formaldehyde experience menstrual disorders. Other studies have found that FAH can damage the genetic make-up of certain cells, which means it may cause birth defects.

Safe Work Procedures

  1. Training: All employees working with formaldehyde or formaldehyde-containing products should be given comprehensive training which should include specific information about the product, how to use it safely, the hazards associated with it, personal protective equipment required, and procedures to follow in an emergency situation.
  2. Material Safety Data Sheets (MSDS's) should be made available to each employee assigned to work with FAH or FAH-containing products. The MSDS should be provided to the employer by the manufacturer and should contain complete and detailed information on the chronic and acute health effects, fire and explosion hazards, and safety precautions. Training and MSDS's are usually required under Right-to-Know laws.
  3. Engineering Controls
    • Substitution: One of the most effective methods of controlling exposure to formaldehyde is to substitute a safer, less toxic material where possible. For example, a dilute bleach may be used to disinfect the exterior of dialyzers and is much safer to use than cleaning agents containing formaldehyde.

      Extreme care must be used when selecting possible substitutes. The alternative should be thoroughly evaluated for possible health effects prior to selection. In many cases,phenols, glutaraldehyde and other cold sterilants may be used as safer alternatives for formaldehyde.

    • Enclosure: Enclosure of the process is another preferred method of controlling worker exposure. The employee is prevented from coming into direct contact with the formaldehyde. The enclosure should be designed with a slight vacuum so that any leaks will result in the flow of external air into the enclosure. The enclosure should be tested regularly to make sure that it is operating properly and that formaldehyde gas is not escaping into the general room air.
    • Local Exhaust Ventilation: Local exhaust ventilation -- where FAH is removed from the worker's breathing area -- should be used to control worker exposure if formaldehyde and associated products must be used. Laboratory work with formalin or specimens preserved in formalin should be done under a fume hood or in a biological safety cabinet. Alternatively, local ventilation with moveable ducting and adjustable air inlets may be used. However, these systems are often less effective because they depend upon being properly adjusted and are more easily tampered with.

      All local exhaust ventilation systems should be checked at installation to ensure that the system is working properly, at three month intervals, and whenever there is a change in process or operations.

      All ventilation systems provided to control contaminants should be exhausted separately from general room air to the outdoors to prevent exposure of other hospital workers to the contaminated air (see the AFSCME Ventilation Fact Sheet).

    • General Dilution Ventilation means providing an adequate number of air exchanges per hour to keep air moving in a work area. In a hospital setting, the use of floor fans and blowers in the ceiling will not protect workers from exposure to formaldehyde.
  4. Respiratory Protection: Respirators should be available for emergency use but they should not be used to protect workers from exposure to formaldehyde on a day-to-day basis. In selecting the proper respirator, it is important to know all of the hazards to which workers may be exposed. The respiratory protection must be carefully selected with a complete understanding of the hazards present.

    IMPROPER USE OF RESPIRATORS IS DANGEROUS. Such equipment should only be used if the employer has a written program that takes into account work place conditions, requirements for worker training, and respirator fit testing. The program should also include medical exams, with emphasis on lung function, to determine an employee's ability to work under the additional strain of wearing a respirator (particularly a negative pressure respirator) as described in OSHA standard 29 CFR 1910.134 (see the AFSCME Respirators Fact Sheet).

  5. Protective Clothing: Employees working with liquid formaldehyde should be provided with impervious clothing, heavy-duty waterproof gloves, face shields (8 inch minimum), aprons, boots and other protective clothing necessary to prevent skin contact with formaldehyde. Employees should wear splash-proof safety goggles where FAH may come into contact with the eyes.
  6. Personal Hygiene: Workers should wash thoroughly, any areas of the body which may have come in contact with formaldehyde:
    • after exposure and at the end of each workday;
    • before lunch breaks and rest periods; and
    • before eating, smoking or using toilet facilities.

Special Precautions

Formaldehyde is flammable and explosive but only in higher concentrations. Explosive concentrations may build up in improperly ventilated storage rooms and fume hoods. Formaldehyde should NEVER be stored near or used with hydrochloric acid because the two chemicals combine to form (bis) Chloromethyl Ether (BCME), a very powerful cancer-causing agent.

Medical Surveillance

Physical symptoms such as respiratory irritation or dermatitis should be an alarm that an employee is being overexposed to formaldehyde. A physician who knows the complete background of the nature of the worker's exposure should perform an examination. Monitoring of the employee's condition should continue as any treatment program is carried out. In addition, any other employees who may also be exposed to formaldehyde in the workplace or may show any symptoms of exposure to FAH should be examined. Medical examinations should be performed on an annual basis with special emphasis on the skin and the respiratory tract, and should include a medical history.

Workplace Exposure Limits

  1. OSHA has issued a revised standard on formaldehyde. It reduces the Permissable Exposure Limit (PEL) from 1 part per million (ppm) to 0.75 as an 8-hour Time-Weighted Average (TWA) with a 2 ppm 15-minute Short Term Exposure Limit (STEL). Finally, the new standard establishes an "Action Level" at 0.5 ppm (8-hour TWA). At the action level, the employer is required to institute a monitoring and abatement program which must include the following:
    • Monitoring. Initial monitoring must be performed by every employer covered by the standard. If the initial monitoring indicates an exposure at or above the action level, the employer must continue monitoring periodically, but at least every 6 months. Monitoring must continue until the results of two consecutive sampling periods taken at least 7 days apart show the exposure level has been reduced to below the action level. Employees must be notified of the results of such monitoring and affected employees or their union representative may observe any monitoring.
    • Regulated Areas. The new standard requires the employer to establish regulated areas where monitoring indicates a level of formaldehyde which exceeds either the PEL (0.75 ppm) or the STEL (2 ppm). The areas must be signed and posted:DANGER ... FORMALDEHYDE ... IRRITANT AND POTENTIAL CANCER HAZARD ... AUTHORIZED PERSONNEL ONLY. Entry into the area must be restricted.
    • Compliance Methods. The employer is required to use engineering controls (described above) and work practice controls, excpt while such controls are being installed, during maintenance and repair activities for which such controls are impossible, and in work situations where engineering and work practice controls do not reduce exposure to below the PEL or STEL.
    • Respiratory Protection. Respirators are required to be worn while engineering controls are being installed, during maintenance and repair activities for which such controls are impossible, in work situations where engineering and work parctice controls do not reduce exposure to below the PEL or STEL, and in emergencies. The standard further specifies the types of respirators which are to be used for varying levels or contamination and requires that such use must be in compliance with 29 CFR 1910.134 (b)(d)(e) and (f), the OSHA Respiratory Protection Standard.
    • Protective Clothing and Equipment. The standard includes requirements for clothing which is impervious to formaldehyde, gloves, safety goggles, face shields, and other personal protective equipment which may be required under 1910.132 and 1910.133. The employer is also responsible for maintaining all personal protective equipment, including laundering of contaminated clothing.
    • Hygiene Protection. The standard requires change rooms for employees who must wear protective clothing, emergency quick drench showers, and emergency eyewash stations.
    • Housekeeping. The standard requires surveying for leaks or spills (including visual inspections), proper maintenance of equipment, spill clean-up procedures, and waste disposal methods.
    • Medical Surveillance. The standard requires medical surveillance for all employees exposed at levels above the action level or the STEL.
    • Hazard Communication. The requirement under the standard for the hazard communication program to be in compliance with the requirements of 29 CFR 1910.1200. This includes employee Right-to-Know training (repeated at least annually). Material Safety Data Sheets (MSDS), product labelling, and all other requirements under the Hazard Communication Standard (or, where applicable, state Right-to-Know laws.)
    • Recordkeeping. The standard requires the employer to establish and maintain accurate records of all monitoring of employee exposure to formaldehyde.
    • ACGIH (American Conference of Governmental Industrial Hygienists) is a standard-setting organization made up of industrial hygienists from governmental agencies and educational institutions. ACGIH has eliminated the old eight hour Time Weighted Average and the 2 ppm Short Term Exposure Limit and adopted a ceiling limit TLV 0.3 for FAH in June 1992. ACGIH has classified formaldehyde as a suspected carcinogen. That designation implies that there may be NO SAFE LEVEL OF EXPOSURE to formaldehyde.
    • NIOSH (National Institute for Occupational Safety and Health) recommends a ceiling limit of 0.1 ppm. NIOSH further recommends that formaldehyde be treated as a human carcinogen.

For more information about protecting workers from workplace hazards, contact the AFSCME Health and Safety Program at (202) 429-1215, or 1625 L Street, N.W., Washington, DC 20036.

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