Table 4. Selected literature on occupational skin exposure to isocyanates.
First author [ref.] | Main conclusion | Origin | Study type | Exposure/occupation | Subjects |
Pronk [19] | Inhalation HDI exposure associated with tasks involving aerosolisation Skin exposure assessed by extraction of HDI from nitrile gloves; associated with paint-handling tasks and glove use HDA detected in 36% of repair shop workers, 10% of industrial workers HDI oligomers main exposure |
Literature search | Cross-sectional study Before and after shift sampling |
HDI oligomers, auto-body repair workers | 68 paired inhalation and skin samples from auto repair shops; 239 urine samples from 45 workers 27 paired inhalation and skin samples from five industrial companies; 52 urine samples from 10 painters |
Robert [55] | MDA detectable in 73% of post-shift urine samples; significantly higher than pre-shift levels Highest MDA levels associated with spraying or hot processes Skin exposure associated with significant MDA levels in urine |
Literature search | Cross-sectional study | MDI polyurethane workers | 169 workers from 19 French factories and 120 controls |
Bello [56] | Quantitative skin wipe sampling method developed 92% of samples under PPE had detectable isocyanate levels, mostly pHDI Highest total isocyanate concentrations associated with spraying and mixing |
Literature search | Cross-sectional study | HDI auto-body repair workers | 185 samples from 81 auto-body shop painters and technicians during different tasks 43 samples under PPE |
Todd [57] | 8–21% of workers exposed to mixtures of chemicals more than OELs; 39–69% of surface samples positive for isocyanates using qualitative CLI Swypes™# PPE and IH controls not adequate |
Literature search | Cross-sectional study | Workers at footwear and equipment factories | 286 personal air samples, 64 surface, tool or hand samples from four factories in Thailand |
Fent [58] | Log-transformed concentrations of HDI in skin of workers correlated with log-transformed product of air concentration and painting time (r=0.79, p<0.001) | Literature search | Cross-sectional study | HDI auto-body spray painters | 13 auto-body spray painters: air and skin samples |
Liu [59] | Skin exposure algorithm using diaries, task-based skin sampling and PPE Median daily skin exposure index estimated for each worker Associated with job category Weakly correlated with daily airborne exposure |
Literature search | Cross-sectional study | Workers in auto-body shops | 232 workers in 33 shops: 893 exposure person-days skin exposure, work diary |
Fent [60] | Isocyanurate predominant isocyanate Dermal HDI concentrations higher in those not wearing gloves/overalls Isocyante detected on skin during 23% of paint tasks Linear mixed modelling identified breathing-zone concentration and paint time significant predictors skin concentration |
Literature search | Cross-sectional study | HDI auto-body spray painters | 47 spray painters dermal and inhalational exposure assessment 15 painters no gloves |
Flack [61] | HDA detected in 76% plasma samples Correlation between plasma HDA and same day dermal exposures, low but significant, correlation between HDA and 20–60 day dermal exposure higher (r=0.36) |
Literature search | Cohort study | HDI auto-body shop painters | 46 spray painters: blood, inhalation and dermal exposures measured 288 tasks |
Liljelind [62] | Average personal air concentrations below Swedish exposure limit Tape stripping used to measure MDI skin exposure Decreasing levels of MDI in consecutive tape strips per site indicate dermal penetration |
Literature search | Cross-sectional study | MDI iron-foundry workers | 19 workers in different areas of foundry; tape strip dermal sampling repeated on five exposed skin areas and air sampling |
HDI: hexamethylene diisocyanate; HDA: hexamethylene diamine; MDA: methylenedianiline diisocyanate; MDI: methylene diphenyl diisocyante; PPE: personal protective equipment; pHDI: polymeric HDI isocyanate; OEL: occupational exposure limit; IH: industrial hygiene. #: skin wipes that provide a visible indication of skin exposure (Colorimetric Laboratories, Inc., Plaines, IL, USA).