Urinary hexane diamine as an indicator of occupational exposure to hexamethylene diisocyanate

Abstract

The occupational exposure of 19 men to hexamethylene diisocyanate (HDI) vapour was monitored during one 8-h shift. It ranged from 0.30 to 97.7 micrograms/m3. This was compared with the urinary output of hexane diamine (HDA) liberated by acid hydrolysis from its conjugates in post-shift samples. The excretion varied from 1.36 to 27.7 micrograms g creatinine, and there was a linear association of HDI air concentration with urinary HDA excretion. The validity of the urinary analysis was confirmed by simultaneous blind analysis in another laboratory. The results had an excellent linear concordance. Thus, it seems that while the gas chromatographic-mass spectrometric detection method requires sophisticated apparatus, the results are very useful to occupational health practices. A biological exposure index limit of 19 micrograms HDA/g creatinine in a post-shift urine specimen is proposed as an occupational limit level of HDI monomer (time-weighted average = 75 micrograms/m3). Most importantly, biological monitoring of HDA is sensitive enough to be used at and below the current allowable exposure limit levels.

Hexamethylendiisocyanat, 2,4‐Toluylendiisocyanat, 2,6‐Toluylendiisocyanat, Isophorondiisocyanat und Diphenylmethan‐4,4′‐diisocyanat – Bestimmung von Hexamethylendiamin, 2,4‐Toluylendiamin, 2,6‐Toluylendiamin, Isophorondiamin und 4,4′‐Diaminodiphenylmethan in Urin mittels Gaschromatographie‐Massenspektrometrie [Biomonitoring Methods in German language, 2017]

“…Verschiedene Probanden-und Arbeitsplatzstudien zeigten eine gute Korrelation zwischen den Diamingehalten im Urin und der Luftkonzentration an TDI Maitre et al 1996;Persson et al 1993; Abb. 1 Strukturformeln der mit dieser Methode bestimmbaren Diisocyanate.…”

“…und Savolainen 1986], HDI [Maitre et al 1996;Tinnerberg et al 1995] sowie IPDI [Tinnerberg et al 1995] und den Diamingehalten im Urin. In Feldstudien konnte zudem gezeigt werden, dass das biologische Monitoring auch zum Nachweis geringer Isocyanatexpositionen geeignet ist.…”

HETA 98-0011-2801, Woodbridge Corporation, Brodhead, Wisconsin.

“…46,47,48,49,50,5152 These studies found that the urine TDA excretion is biphasic, with the excretion occurring in both a fast and slow phase. The predominant fast phase is indicative of recent exposure, whereas the lesser slow phase reflects urinary elimination of degradation products of TDI-modified proteins and erythrocytes.…”

Evaluation of Hexamethylene Diisocyanate as an Indoor Air Pollutant and Biological Assessment of Hexamethylene Diamine in the Polyurethane Factories

“…However, this result is low compared to work performed by Brorson et al (1990) where it was reported that the mean value of isocyanates metabolite at the end of working shift was 20 µmol/mol creatinine. Similarly, Maitre et al (1996) have measured a value of 12 µmol/mol creatinine for diisocyanates exposure at the same concentration from a survey of workers.…”