You could explain to the patient that toluene diisocyanate (TDI) is not the same chemical as the chemical in the spray paint. Both toluene and toluene diisocyanate are liquids, but their chemical structures are different, as are their toxicities. Toluene is a common solvent found in many household products; its toxicity is low, and at low doses (less than 100 ppm) it normally causes few symptoms. On the other hand, TDI is very irritating to the eyes and respiratory tract and may cause bronchospasm at levels less than 1 ppm. Furthermore, TDI can sensitize exposed individuals and cause coughing spasms at even lower levels than the original exposure, and this does not occur with toluene.

See (b) above.

There is little clinical benefit in measuring blood toluene levels or levels of toluene metabolites such as hippuric acid in the urine. Treatment would not be altered regardless of the results. The only available comparison data are from either deliberate toluene abusers or asymptomatic workers with chronic exposure, and it is unclear how such data would apply to this patient.

See (c) above.

There are few data to suggest that toluene is carcinogenic. Earlier incidents of cancer occurring after chronic toluene exposure were caused by toluene’s significant contamination with benzene, which is a known carcinogen. (Benzene is no longer a contaminant of toluene.) The patient can be reassured that a single exposure to toluene is unlikely to cause or contribute to the development of cancer.

See (d) above.