These monitors are small and lightweight and will not interfere with employee activities. 3M™ Organic Vapor, Ethylene Oxide and Formaldehyde monitors sample airborne contaminants by the simple process of diffusion. Easy-to-use, just clip to shirt lapel, collar, or pocket. Simple and convenient with no batteries, hoses or pumps required. 3M™ monitors can also be used for area monitoring, if sufficient air flow exists. 3M™ monitors can be analyzed in the lab of your choice or returned for analysis when purchased with prepaid analysis. The 3M™ Organic Vapor Monitor 3500 has a single charcoal sorbent wafer for easy collection of organic vapors and can be used for most applications. Can be analyzed by gas chromatography in your lab. 18-month shelf life. The Organic Vapor Monitor 3520, with backup section uses primary and back-up sorbent pads for sampling demanding environments. Especially suited for monitoring compounds like acrylonitrile, butadiene and methylene chloride for which activated carbon shows limited capacity. It has (2) stages for increased sampling capacity. Each monitors more than 125 organic vapors. 18-month shelf life. The Ethylene Oxide Monitor 3551 is designed for sampling personnel or work areas in the pharmaceutical, health care and chemical industries. The monitor utilizes brominated carbon to collect and convert the reactive ethylene oxide to a more stable chemical derivative called 2-bromoethanol. It meets OSHA’s requirement for accuracy within +/- 25% for 8-hour samplings at 1 ppm. The 3M™ Formaldehyde Monitor 3721 are designed for measuring exposure to formaldehyde in the chemical, pulp/paper, foundry and textiles industries. Meet OSHA accuracy requirements of +/-25% for 8-hour TWA sampling. Ships Direct F.O.B. Mfg. ** PE** 3M Warning GD-1