Prepaid analysis address is: B.I.C. Chemistry Department, 11001 Hampshire Ave. S.,
Mpls., MN 55438
The 3M™ Formaldehyde Monitor 3720, with Prepaid Analysis uses the proven scientific principle of diffusion, which is the gradual mixing of molecules of two or more substances. It monitors personnel or work areas in health care, laboratories, and in the chemical, pulp/paper, foundry and textile industries. Analysis procedure is available upon request. The monitor uses a bisulfite-impregnated filter and is analyzed by colorimetry. It can be used for 8 hour TWA sampling to meet the OSHA requirement of +/-25% accuracy at 0.5-5.0ppm. However, this monitor does not have the sensitivity for short term exposure limit (STEL) monitoring. It has an 18-month shelf life.