Formaldehyde and Other Aldehydes
Formaldehyde is widely used on campus for preserving or fixing biological cells and tissues. Formaldehyde is a suspected human carcinogen and a suspected reproductive hazard. Formalin is an aqueous solution that generally contains a 3 to 10% dilution of formaldehyde from the original 37-40% solution. Paraformaldehyde is the crystallized polymer of formaldehyde that is typically dissolved in solution for cell and tissue fixation. Typically, 3-10% formalin or paraformaldehyde solutions are used to perfuse or fix tissues.
The Occupational Safety and Health Administration (OSHA) has set the Permissible Exposure Limit (PEL) at 0.75 ppm averaged over an 8 hour work day. The action level is set at 0.5 ppm, and is the level at which action must be taken to reduce exposures. OSHA also mandates that no employee shall be exposed to formaldehyde in concentrations that exceed 2 ppm as a 15-minute Short Term Exposure Limit (STEL). The American Conference of Governmental Industrial Hygienist (ACGIH), a non-profit, non- governmental corporation recommends a more conservative exposure level of 0.3 ppm, and this is a ceiling (or never-to-be-exceeded) level.
Given the carcinogenic and sensitizing properties of formaldehyde, EHSRM recommends keeping exposures as low as possible, and strives to meet the NIOSH Recommended Exposure Level (REL) of 0.016 ppm. This generally requires working in a chemical fume hood whenever formalin or formalin-preserved specimens are handled. Often, researchers transfer specimens from formalin to ethanol or isopropanol. Once the transfer has taken place, it is usually safe to work with them outside the fume hood. Snorkels, placed within one duct diameter of the sample, may help remove nuisance vapors that can cause headaches or eye and respiratory irritation.
Unless there is objective data that shows the presence of formaldehyde cannot result in exposures above the action level or STEL, employee exposure monitoring is required. The monitoring can be conducted by EHSRM. If you are starting a new process that uses formaldehyde or if you are unsure if your lab has ever been monitored for formaldehyde exposure, please call EHSRM at 474-6771 to establish a monitoring plan. There are requirements on the frequency of monitoring based on the results of the initial monitoring.
Where monitoring shows that the TWA of the PEL and/or STEL has been exceeded, all entrances to the lab must be labeled with a sign that reads:
Exposure to formaldehyde can be irritating to the eyes, nose, and upper respiratory tract. In certain individuals, repeated skin exposure to formaldehyde can cause sensitization that may result in allergic dermatitis.
Here are a few tips to help limit your exposure:
- All work with concentrated formalin solutions must be done in a chemical fume hood. If this is not possible, contact EHSRM to set up personal and area exposure monitoring.
- When dissecting or working with tissue specimens perfused with or fixed in formaldehyde, do so in a hood or allowing tissues to air out in a well-ventilated area prior to handling the specimen. Eliminating puddles of formaldehyde in the specimen by rinsing or blotting the excess with paper towels can reduce exposure.
- Wear nitrile (preferred) or neoprene gloves when handling formaldehyde.
- Wear splash goggles or glasses with side shields as formaldehyde can cause irreversible damage.
- Wear full buttoned front or back closing lab coats and closed toe shoes
- Wash the work area as well as your hands after each use and before eating or drinking.
- Employees that need to wear a respirator due to their exposure concentrations must be enrolled in the UAF Respiratory Protection Plan. Please contact x6771 if you feel you need to wear a respirator. OSHA requires a medical clearance, training, and annual fit-testing for all occupational respirator use. This is provided at no charge to UAF employees who demonstrate a need to wear a respirator at work.
- Do not take home any equipment or clothing that is contaminated with formaldehyde.
Formaldehyde gas, mixtures, or solutions composed of 0.1 % formaldehyde or greater is subject to the hazard communication requirements. Labels on materials that are capable of releasing formaldehyde levels of 0.1 ppm to 0.5 ppm should at a minimum, list the name and address of the responsible party, and state that the physical and health hazard information is available from the employer and from Safety Data Sheets (SDS). For materials capable of releasing formaldehyde at levels above 0.5 ppm labels should also include the works “Potential Cancer Hazard”. An SDS should also be available for the employees.
Special Safety Precautions
If formaldehyde contacts the body flush with water in an emergency eye wash or shower for at least 15 minutes. Call 911 for emergency medical attention.
All solutions of formaldehyde and tissues preserved in formalin must be stored in tightly sealed, properly labeled, containers to prevent leaks, spills, and evaporation.
Do not pour formalin or formalin waste into sinks or drains. Formalin waste solutions must be placed in tightly sealed, labeled containers and picked up for disposal by the EHSRM Hazardous Waste Pickup, 474-5617. Trace amounts of formaldehyde solutions such as puddles left on a tray after fixing tissue or examining a specimen may be absorbed with an absorbent material. The absorbent material should be placed into a tightly sealed bag and picked up for disposal by the EHSRM Hazardous Waste Pickup.
Clean up small spills of dilute formalin only if you have the appropriate equipment to do so (e.g., gloves and eye protection). Materials used to absorb the materials should be placed into a tightly sealed bag and disposed of by the EHSRM Hazardous Waste Pickup.
Do not attempt to clean up large spills. If a spill occurs that causes eye, nose, or throat irritation, evacuate the area, close all doors, notify other building occupants near by, and call 911 or EHSRM Hazardous Waste Pickup at 474-5617. The Emergency Dispatch business line can be reached at 474-7721.
To learn how to request a Hazardous Waste Pickup or call 474-5617 or 474-5197.