Toluene 2,4-diisocyanate asthma caused

Certain LMW agents will cause OA via a poorly defined mechanism. Only about 20% of workers with OA to toluene diisocyanate (TDI) have IgE detectable to TDI indicating that IgE antibody may be more an indicator of exposure rather than a mediator of the disease [10], Similar data exist for workers with asthma caused by plicatic acid from western red cedar [11], The inability to detect IgE antibody in the majority of these workers may be based in technical issues such as the nature of the chemical-protein... 

Important commercial isocyanates include the diisocyanate monomers toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), and MDI-, TDI-, and HDI-based isocyanates (e.g., prepolymers and polyisocyanates). World-wide production volume is estimated at over 12 billion lb. Isocyanates (diisocyanates, polyisocyanates, and prepolymers) all cause similar health effects, most commonly asthma [32]. Isocyanates are reported to be the leading attributable cause of work-related asthma [16]. Isocyanates are potent sensitizers that can trigger a severe and potentially fatal asthma attack in sensitized persons at very low isocyanate exposure levels [16]. Toluene diisocyanate is reasonably anticipated to be a human carcinogen by National Toxicology Program. 

Respiratory sensitizer May cause allergy or asthma symptoms or breathing difficulties if inhaled 1 Danger Human evidence of respiratory hypersensitivity, tmd/or positive from animal testing Polyisocyanates, such as toluene diisocyanate acid anhydrides, such as tiimellitic anhydride, formaldehyde... 

Urethane resins may contain free diisocyanates, which are usually respiratory irritants and sensitizers that have caused rhinitis and asthma (Estlander et al. 1992). 2,4-toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI) are important respiratory sensitizers, whereas 4,4 -diphenylmethane diisocyanate (MDI) is the most important skin sensitizing diisocyanate (Estlander et al. 1992). Two-component systems in which addition of a diisocyanate to the polyhydroxyl compound immediately before use carry the greatest risk of skin sensitization. Partial polymerization of diisocyanates to increase molecular weight and reduce volatility are used to decrease the risk of sensititization (Mathias 1984). See also the chapter on polyurethane resins in this book. 

The toxic route is primarily inhalation. The vapor pressure of this compound at ambient temperature is very low, 0.00014 torr at 25°C. However, when heated to about 75°C, the acute health hazard is greatly enhanced (Hadengue and Philbert 1983). The acute toxic symptoms were found to be similar to those of toluene-2,4-diisocyanate and other aromatic isocyanates. Inhalation of its vapors or particulates can cause bronchitis, coughing, fever, and an asthma-like syndrome. Other symptoms were nausea, shortness of breath, chest pain, insomnia, and irritation of the eyes, nose, and throat. The immunologic response, however, varied among humans. Exposure to 0.1-0.2 ppm for 30 minutes is likely to manifest the acute toxic effects in humans. 

---