TDI is one of a group of compounds known as aromatic diisocyanates. At room temperature, TDI is a colourless to pale yellow liquid with a sharp acrid odour and relatively high volatility.
Hazardous properties
Like most diisocyanates, exposure to TDI either by inhalation, ingestion or skin contact can lead to sensitisation (1). It is irritating to the skin (causing dermatitis) and eyes and can affect the respiratory system causing dyspnoea (breathing difficulty), pulmonary oedema and asthma.
Occurrence/Uses
TDI is used extensively as a curing agent in the manufacture of flexible polyurethane foams and elastomers.
Detectors available
Colorimetric paper tape (0–200 ppb)
Suggested alarm levels
5 ppb
Notes
(1) Sensitisation is a phenomenon occurring in some individuals, whereby exposure to a substance leads to those individuals having an increased sensitivity to the effects of that substance.