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I. The Issue:

Formaldehyde is a fungicide and bactericide commonly used to preserve biological specimen. Many middle and high school science curricula utilize preserved biological specimen for demonstration and dissection purposes. The major problems associated with using specimen preserved in formaldehyde is that the material is a confirmed carcinogen as well as a serious respiratory irritant. As a result, active mechanical ventilation is required to prevent the accumulation of potentially dangerous concentrations of formaldehyde vapors. This task is hampered by the fact that formaldehyde vapors are heavier than air and tend to settle near the floor in a classroom or laboratory. This can be extremely problematic in buildings where the ventilation system is mounted on the ceiling or designed for air contaminants that are lighter than air and naturally rise.

II. The Approach Taken:

Routine inspections of the high school science area have often resulted in the detection of formaldehyde odors in the biology labs or nearby classrooms. A survey of the staff indicated that formaldehyde odors were a common nuisance each year when anatomy instruction was taking place.

A review of the biological specimen maintained by school department indicated that most of the preserved specimen owned by the school department had been treated with formaldehyde or a formaldehyde based material. As a result, the handling or dissection of many of these items represented a variety of potential health and safety issues.

A survey of scientific supply vendors determined that a number of less toxic or nontoxic alternatives are readily available. A variety of replacement preservatives and biological specimen free of formaldehyde are available in the market place. Not all substitutes are free of potential hazards, but most have eliminated the potential exposure to a confirmed carcinogen while also reducing the impact on indoor air quality.

Based on the availability of less toxic alternatives, the school department has been encouraged to replace its existing inventory of formaldehyde preserved specimen with newer less hazardous specimen. This approach could significantly improve the indoor air quality within the science area and adjoining classrooms while also reducing the exposure risk of the instructor and students working with the specimen. In addition, the elimination of the use of formaldehyde would decrease the need to augment and enhance the ventilation system serving the biology laboratories. Another potential cost savings would be related to a reduction in the amount of hazardous waste that would be generated by the science department and need special treatment or disposal.

Barring the replacement of all formaldehyde preserved specimen with less toxic substitutes, the Board of Health has recommended that all dissections involving formaldehyde preserved specimen be completed only in areas that have been provided with adequate mechanical ventilation capable of eliminating the respiratory hazards created by the formaldehyde. The federal Occupational Safety and Health Administration has placed a high level of importance on minimizing occupational exposure to formaldehyde. Federal regulation 29 CFR 1910.1048 has established 0.5 parts per million (ppm) as an action level where an employer must take action to minimize an employee's exposure to formaldehyde. This regulation has also established a maximum permissible exposure limit for an adult worker over an eight hour day of 0.75 PPM, and a short term exposure limit (15 minutes) of 2 PPM These exposure standards have been devised for adult workers in an occupational setting and cannot be directly applied to a school setting. However, these standards do provide a metric for comparison. In addition, most industrial hygienists tend to apply a safety factor for children due metabolic and developmental differences between children and adults, and as a result reduce acceptable chemical exposure standards correspondingly. This is significant because the odor threshold or the concentration at which most individuals can smell formaldehyde is 0.8 PPM This means that in most cases if you can smell formaldehyde then you have exceeded the federal action level and may possibly exceed the exposure limit if you have prolonged exposure to the odor.

The Board of Health has also informed the school department staff of the need to manage dissection waste as hazardous waste due to the formaldehyde content. Our intent was to ensure that all liquid preservatives and bulk quantities of preserved tissues were properly managed to prevent an environmental release of the material.

III. Observations Made:

Staff complaints and follow up inspections have resulted in the detection of formaldehyde odors in the science area and adjacent classrooms at the high school. These observations have coincided with the times when preserved specimen have been used in the biology classes.

Most of the biological specimen used by the school department have been preserved in formaldehyde. This suggests that the open handling and dissection of these samples may pose a potential health and safety risk to the user as well as an indoor air quality concern for the school.

Many classrooms where dissections have historically been conducted have not been provided with adequate mechanical ventilation capable of removing formaldehyde vapors from the school. This re-enforces the need to either relocate the dissection activities to a different classroom/laboratory equipped with enhanced mechanical ventilation or to adopt a safer alternative. Failure to do so will prolong the risk of occupational exposure to the students and staff while also adversely impacting the indoor air quality of the school.

It was also noted that much of the staff appears to be complacent with regard to the hazards associated with exposure to formaldehyde. Years of handling the material has caused some staff members to assume that the material is relatively nontoxic and the precautionary measures are reactionary in nature. As a result many safety advisories continue to go unheeded.

IV. Problems or Concerns Noted:

V. Actions Taken:

A. Identified the problem and informed the staff of potential hazards.

The initial step was to investigate and determine the source of odor complaints registered by the school department staff and detected during routine inspections. The source of the formaldehyde odors was quickly traced to the biology classrooms. The potential hazards and solutions to this problem were then discussed with the staff in an effort to provide a short term improvement.

B. The inventory of biological specimen were then surveyed to determine the extent of the problem.

This effort found that the majority of the specimen in the school inventory had been preserved in formaldehyde. Consequently, the handling or use of these items poses a potential health and safety concern and may adversely impact indoor air quality.

C. Scientific supply vendors were surveyed regarding the availability of non or less toxic alternatives.

This survey determined that a variety of more benign and environmentally friendly alternatives were readily available.

D. The Board of Health has recommended that the school department replace its inventory of formaldehyde preserved specimen with less hazardous substitutes.

This approach could reduce occupational exposure concerns, improve indoor air quality, alleviate the need to implement costly modifications to the school ventilation system, and may reduce the volume of hazardous waste generated by the school.

E. Pending the adoption of a less toxic alternative, the Board of Health has recommended that all activities involving formaldehyde or preserved specimen be conducted with the aid of adequate mechanical ventilation.

The intent of this directive was to improve and protect the indoor air quality at the school and to reduce the chemical exposure hazard for the user.

F. The school has initiated the collection of all dissection waste for disposal as hazardous waste.

The purpose of this exercise is to prevent the inadvertent release of hazardous materials to the environment.

Lessons Learned:

1. If you can smell formaldehyde then you may have exceeded the OSHA action or exposure limits.

2. Less toxic alternatives are readily available.

3. Familiarity with formaldehyde may cause users to become complacent with regard to the health hazards associated with the substance .

4. Many school laboratories have not been constructed with adequate mechanical ventilation capable of properly exhausting formaldehyde vapors from the building. This provides a strong incentive for seeking and adopting a less toxic alternative.

Tips and suggestions:

1. Train and inform your staff of the hazards associated with formaldehyde exposure. This may enable you to identify and develop a supporter who may assist your efforts to mitigate this hazard.

2. Replace existing specimen preserved in formaldehyde with less toxic specimen. This step may eliminate or at least significantly reduce your health and safety concerns associated with animal dissection and demonstrations.

3. Use formaldehyde and formaldehyde preserved specimen only in areas where mechanical ventilation can properly prevent the build up of formaldehyde. Failure to do so may result in the accumulation of dangerous concentrations of formaldehyde.


During this assessment I relied upon the guidance and assistance offered by the staff of the regional office of the federal Department of Labor Occupational Safety and Health Administration. I encourage you to contact your regional OSHA or state occupational hygiene offices prior to initiating a comparable review.

prepared by Todd H. Dresser, Environmental Engineer
(formerly of)
Burlington Board of Health, 29 Center Street, Burlington, MA 01803

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