| First author [ref.] | Main conclusion | Origin | SIGN grade | Study type | Exposure/occupation | Subjects |
| Petsonk [64] | 27% of workers in areas with high potential for liquid MDI exposure reported new-onset asthma-like symptoms versus 0% in low-potential areas Skin staining and MDI on clothes, cleaning up MDI was associated with these symptoms Asthma symptoms were associated with variable airflow limitation and MDI-specific IgE Air monitoring data (six personal breathing zone samples) showed no detectable MDI A single glove wipe sample was taken and had 0.078 mg MDI The skin may be a site for sensitisation and subsequent risk for development of respiratory symptoms | Literature search | 2+ | Cohort (1-yr follow-up) | MDI: wood manufacturing plant | 214 plant employees, 83% participated in follow-up survey Questionnaires prior to use of MDI and every 6 months thereafter Serial peak flows, spirometry, methacholine challenge, MDI-IgE, skin prick testing performed at certain times in selected workers |
| Lenaerts-Langanke [65] | Population: 50% reported skin exposure 6.5% of the pressure grouters had MDI-related respiratory symptoms Two had positive MDI-specific inhalation challenge Air exposures were very low (<1 ppb) 6 out of 8 pressure grouters with heavy skin exposure MDI metabolites in urine Reported skin irritation from MDI uncommon MDI skin exposure common MDI sensitisation through skin contact possible Important to prevent skin exposure | Literature search | 3 | Cross-sectional study | MDI: coal miners | Three populations: 216 pressure grouters who inject MDI polyurethane foam (55 control miners) 245 exposed miners Eight pressure grouters with heavy polyurethane skin exposure |
| Shahzad [67] | Asthma prevalence 10.8% (69/641) Multivariate analysis: asthma associated with educational status, ethnicity, smoking, glove use (never use OR 3.28, 95% CI 1.72–6.26), perceived allergy, duration of work Protective effect of glove use may be due to protection of skin from sensitising chemicals | Literature search | 2- | Cross-sectional study | Leather tannery workers in Pakistan | 641 workers in 95 tanneries, all workers enrolled working with tanning process Questionnaire No exposure information |
| Bernstein [66] | Based on questionnaire-derived diagnoses of 243 workers: 4% workers with occupational asthma, 36% occupational rhinitis, and 11% irritant lower respiratory symptoms Two workers (0.4%) had MDI-specific IgG, both worked in finishing area where they had direct MDI skin contact Plant designed to minimise MDI exposures 24-h·day−1 air monitoring area samples All air levels <0.005 ppm Selected workers further medical evaluation: three cases occupational asthma from MDI (1.2%) and one case MDI-induced cutaneous anaphylaxis (positive MDI skin test and MDI-IgE) These four workers worked in areas with potential MDI skin contact Conclusions: low prevalence of sensitisation and occupational asthma Authors recommend avoid MDI skin contact | Literature search | 3 | Cross-sectional study/case series isocyanate asthma | MDI: polyurethane mould plant | 243 workers exposed to MDI: questionnaire and serum antibody tests 147 workers on polyurethane mould lines 3 cases of isocyanate asthma |
| Donnelly [68] | Nurse with MDI asthma Case confirmed by specific inhalation challenge with MDI cast material (39% decreased FEV1) | Literature search | 3 | Case study | MDI: hospital synthetic plaster casts | One nurse working with MDI-containing plaster casts for 4 yrs |
| Nemery [69] | Surface worker who handled half-empty MDI drums at the mine without safety precautions developed probable isocyanate asthma Risk of isocyanate exposure with polyurethane rock consolidation | Literature search | 3 | Case study | MDI: coal miners | Surface worker from coal mine |
| Dernehl [70] | Mentions personal experience: isocyanate skin exposure increases risk asthma | Cited in article | 3 | Personal experience | MDI | Workers with respirator protection and repeated skin contact |
SIGN: Scottish Intercollegiate Guidelines Network; MDI: methylene diphenyl diisocyanate; Ig: immunoglobulin; FEV1: forced expiratory volume in 1 s.