“…The person-related 1,5-naphthylene diisocyanate concentrations were between 0.2 and 15 μg/m 3 (median: 3 μg/m 3 ) and the 1,5-diaminonaphthalene values in urine were 0.7-81 μg/l (median: 8.4 μg/l) with a detection limit of 0.1 μg/l. A significant correlation between the concentrations of 1,5-diaminonaphthalene in urine and the concentrations of 1,5-naphthylene diisocyanate in the air was found (Sennbro et al 2006). If one takes these correlation data as a basis, the concentration of 50 μg 1,5-naphthylene diisocyanate/m 3 recommended in the MAK documentation would correspond to a 1,5-diaminonaphthalene concentration of 137 μg/l urine.…”