TDI in Solvent Atmosphere

This method is designed to permit the determination of TDI in an atmosphere also containing solvent vapour. It is based on the fact that TDI 

The required reagent is based on acetic acid (0 6 n) and dimethyl-aminobenzaldehyde (1%). 0 5 g of dimethylaminobenzaldehyde is dissolved in 25 ml of glacial acetic acid and diluted with 25 ml of distilled water. The solution is stored in a brown bottle in the refrigerator and freshly prepared daily. 

These must always be handled as materials which carry a health risk. Diamines seriously damage the eyes and in certain cases cause serious burns on contact with the skin. Both vapour and liquid are capable of producing hypersensitivity in certain people, resulting in dermatitis and/or an asthmatic type of response. 

Some diamines are undoubtedly active cancer-promoting agents others may have cancer-promoting capabilities if exposure to vapour or skin contact occurs over long periods of time. In particular, one technically and commercially important diamine has acquired the reputation of a potential carcinogen over later years this is 4,4 -methylene bisorthochloroaniline (MOCA) and particular hygiene precautions are required in its use. 

---