Many sampling strategies may be used to quantify the airborne concentrations of formaldehyde. Small personal pumps with absorbent tubes (integrated air sample) and colorimetric (real-time) badges are two such methods.

Here at the University of Maryland, Baltimore several applications utilizing formaldehyde can be found in various laboratories. One type of use is the preservation of tissue samples, in particular for routine histology applications. Some laboratories prepare tissue samples for examination under the electron microscope. Formaldehyde can be used as a fixative, whereby the tissue is preserved in its life-like state. The tissue is dehydrated and embedded into paraffin so that cross-sections may be cut for staining. One such laboratory in the Bressler Research Building obtains tissues preserved in containers, usually with no more than 50ml of formaldehyde. The laboratory was sampled for airborne concentrations, whereby levels were found to be below 0.3 ppm of formaldehyde. ChromAir Badges were worn by four (4) histotechnicians and five (5) were placed in the laboratory to provide general area exposure data. The sampling technique utilized passive air badges whereby the formaldehyde gas will diffuse through the 6 cells to an indicator layer. The indicator layer will then produce a color change corresponding to an exposure dose. If your laboratory utilizes formaldehyde and you are concerned about possible exposures, please feel free to contact the Occupational Safety and Health Department at 410.706.3490 (OS) for a hazard assessment. We can determine the best sampling strategy for your area in order to quantify any airborne contamination.

Below are the sample results taken for this histology laboratory:

On June 3, 1998 OS reviewed the formaldehyde badges used for sampling in labs 3-007 and 3-009 BRB. All of the results were below the 0.3 ppm minimum detection level of the badges. The OSHA exposure limit for formaldehyde is 0.75 ppm (TWA). The badges were made by K&M Environmental (see attached informational sheet). These results must be provided to all employees who participated in the monitoring or who work in the area where the monitoring was conducted.