DIETHANOLAMINE IN COOLING LUBRICANT CONCE NTRATES - RESULTS OF AN INVESTIGATION PROGRAM IN 1996

In Germany, the use of diethanolamine in water-mixable cooling lubrica nts was prohibited with the coming into force of TRGS 611 (1993). In t he beginning, it was very difficult for the manufacturers to adapt to the new legal situation. In some cases, the limit value of 0.2% of the cooling lubricant concentrate was clearly exceeded. In 1996, the comp etent German Berufsgenossenschaften, the Office for Occupational Safet y of the Land North Rhine-Westphalia and the Berufsgenossenschaftliche s Institut fur Arbeitssicherheit - BIA joined together in a measuremen t programme. The latter was aimed to investigate whether cooling lubri cants available on the market satisfied the legal requirements. 51 sam ples were analysed. Six of them showed diethanolamine concentrations a bove the admissible limit, the maximum concentration reaching 0.85%. T hese quantities could be due to contaminated basic products. The addit ion of triethanolamine, which may contain diethanolamine, is particula rly critical. Manufacturers of cooling lubricants are therefore recomm ended to make sure the utilised triethanolamine is clean.