HBM4EU diisocyanates study – results from a collaborative European human biological monitoring study on occupational exposure

Diisocyanates have long been a leading cause of occupational asthma in Europe, and they are now restricted under the REACH regulation. As part of the European Human Biomonitoring project (HBM4EU), we conducted an occupational exposure survey on diisocyanates in five European countries. 116 workers were recruited across four job categories: (1) Use of diisocyanates-based glues, adhesives or sealants; (2) Polyurethane coating of large surfaces; (3) Spray application of urethane foam; (4) Spray coating of vehicles. Fifty controls (within the same companies) were also recruited. The study collected urine samples (analysed for diisocyanate-derived diamines and lysine conjugates), blood samples (analysed for diisocyanate-specific antibodies, inflammatory markers, and diisocyanate-specific haemoglobin adducts), buccal cells (micronucleus analysis) and measured fractional exhaled nitric oxide (FeNO). In addition, occupational hygiene measurements (air monitoring and skin wipe samples) and questionnaires were collected. Initial results showed significant airborne exposures for some tasks (spraying polyurethane foam insulation), with elevated urinary diamine levels compared to controls (p<0.001), and detection of the specific MDI-lysine conjugate. Most workers did not show increased FeNO, but some individuals had elevated results (controls max 30 ppb (n=49), workers max 161 ppb (n=108). Further ongoing data analysis will be presented.