The 571 Aldehyde Monitor is our most popular badge since it can be used to monitor for formaldehyde along with other aldehydes. Unlike other aldehyde badges, the 571 can used to monitor formaldehyde in the air for a 15 minutes STEL, as well as a 8 hour PEL, and for indoor air quality, 24 to 72 hours.
Aldehydes are collected on a glass fiber filter treated with 2,4-dinitrophenylhydrazine and phosphoric acid. The sample filter is extracted with acetonitrile and analyzed by HPLC using a UV detector. Badges are assembled under a blanket of nitrogen to reduce background levels.
For Cidex (glutaraldehyde) and Cidex OPA (o-phthaldehyde), use the 581 badge for STEL/Ceiling monitoring.
Customers that are going to use the NIOSH REL to evaluate their formaldehyde results should use the 581 badge, not the 571. The NIOSH REL is 0.016 ppm, which is over 40 times below the OSHA PEL of 0.75 ppm. So the fast sampling 581 with an 8 hour reporting limit of 0.0014 ppm is preferred.