title: Biological monitoring of isocyanates and related amines. III. Test chamber exposure of humans to toluene diisocyanate.
abstract: Five men were exposed to toluene diisocyanate (TDI) atmospheres for 7.5 h. The TDI atmospheres were generated by a gas-phase permeation method, and the exposures were performed in an 8-m3 stainless-steel test chamber. The mean air concentration of TDI was ca. 40 micrograms/m3, which corresponds to the threshold limit value (TLV) of Sweden. The inhaled doses of 2,4- and 2,6-TDI were ca. 120 micrograms. TDI in the test chamber air was determined by an HPLC method using the 9-(N-methylaminomethyl)-anthracene reagent and by a continuous-monitoring filter-tape instrument. After hydrolysis of plasma and urine, the related amines, 2,4- and 2,6-toluenediamine 2,4-, and 2,6-TDA), were determined as pentafluoropropionic anhydride (PFPA) derivatives by capillary gas-chromatography using selected ion monitoring (SIM) in the electron-impact mode. The urinary elimination of the TDAs showed a possible biphasic pattern, with rapid first phases for 2,4-TDA (mean t1/2 for the concentration in urine, 1.9 h) and for 2,6-TDA (mean t1/2 for the concentration in urine, 1.6 h). The cumulative amount of 2,4-TDA excreted in urine within 28 h ranged from 8% to 14% of the estimated dose of 2,4-TDI, and the cumulative amount of 2,6-TDA in urine ranged from 14% to 18% of the 2,6-TDI dose. The average urinary level of 2,4-TDA was 5 micrograms/l in the 6 to 8-h sample (range 2.8-9.6 micrograms/l), and the corresponding value for 2,6-TDA was 8.6 micrograms/l (range, 5.6-16.6 micrograms/l). Biological monitoring of exposure to 2,4- and 2,6-TDI by analysis of 2,4- and 2,6-TDA in urine is feasible.
authors.affiliation: Department of Occupational and Environmental Medicine, University Hospital, Lund, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Skarping
authors.forename: T
authors.initials: T
authors.lastname: Brorson
authors.forename: C
authors.initials: C
authors.lastname: Sangö
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects; D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008452:Maximum Allowable Concentration; D008657:Metabolic Clearance Rate / Q000502:physiology; D008875:Middle Aged; D016273:Occupational Exposure; D010655:Phenylenediamines / Q000493:pharmacokinetics; D012307:Risk Factors; D014051:Toluene 2,4-Diisocyanate / Q000009:adverse effects / Q000493:pharmacokinetics*
chemical_list: D000395:Air Pollutants, Occupational; D010655:Phenylenediamines; D014051:Toluene 2,4-Diisocyanate; C025235:2,6-diaminotoluene; C010914:2,4-diaminotoluene