Foam Application

Foam Application

Question: We want to collect 15-20 minute Isocyanate sample to evaluate workers exposure to isocyanates. What method should we use?. Thank you G.S.

Answer:  Hello G.S. Thank you for your question. Isocyanates are regulated at Ceiling limit of 0.020 ppm and TWA limit of 0.005 ppm (Ontario, Canada, 2017). You are asking about 15 min sampling, so we assume that you need to measure ceiling value during brief application of isocyanate.  In general, 15 minute samples have notoriously poore reproducibility. The results are affected by direction of air draft, how little of how much isocyanate product were used  and even worker’s habits. In other words you have high chance of getting non-reproducible high or low reading. To obtain more or less representative picture, you may want to collect multiple short term samples on the same  worker.

Air Sampling cassettes

Air sampling cassettes

There are 3 methods that are generally used for assessment of di-isocyanates: OSHA 42/47, NIOSH 5525, and IsoCheck methods.

IsoCheck method offers the best sensitivity, but it is hard to find a lab that can perform the test. Sorry we do not offer this test either.

NIOSH 5525 offers sensitivity of 0.001 ppm for 15 min samples. This sensitivity is sufficient for the Short Term Sampling of such di-isocyanates like HDI, MDI, TDI and IPDI

OSHA 42/47 is the least sensitive and can detect only 0.005 ppm of isocyanates on 15 min sample. This method is not recommended for short sampling.

If you need to complete Isocyanate assessment, please contact us for a free, no-obligation quote.

LCS Laboratory