Browsing by Author "Stouten, Hans"

Now showing 1 - 2 of 2

DECOS and SCG Basis for an Occupational Standard : n-, iso-, sec-, and tert-Butyl acetate
(Arbetslivsinstitutet, 2002) Stouten, Hans; Bogaerts, Wim
The butyl acetates are colourless, flammable liquids with a fruity odour. They are slightly soluble or insoluble in water, and soluble in ethanol and ether. The butyl acetates occur in natural and food products, but are also produced chemically. The main use of butyl acetates is as solvents in paints and lacquers. There are no quantitative data on the absorption of butyl acetate isomers. Butyl acetates are quickly metabolised in the body to acetic acid and their respective butanols; tert-butyl acetate, however, slower than the tree other isomers. Based on human experimental data the critical effect of occupational exposure to n-butyl acetate is irritation of eyes, skin and mucous membranes. For isobutyl acetate, irritation is probably the critical effect, but the data are less convincing. For the other isomers, there are no data indicating a critical effect.
The Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and the Dutch Expert Committee on Occupational Standards : 129. Chlorotrimethylsilane
(Arbetslivsinstitutet, 2002) Stouten, Hans; Rutten, Fons; Gevel, Iris van de; Vrijer, Flora de
Chlorotrimethylsilane is a colourless liquid with a sharp hydrogen chloride-like odour. The chlorotrimethylsilane vapour is heavier than air, and travels along surfaces. At elevated temperatures or combustion, the substance decomposes producing corrosive and toxic vapours. It violently reacts with water producing hydrogen chloride. Hydrogen chloride is also released upon contact with surface moisture. Because of the high reactivity, chlorotrimethylsilane must be manufactured, stored, and used in airtight, highly specialised installations. Chlorotrimethylsilane is used as an intermediate in the production of silicone fluids, as a silylating agent, and as a catalyst in the production of propylene oxide. There were no data available on the toxicokinetics of chlorotrimethylsilane. No methods for monitoring chlorotrimethylsilane in air or biological samples were found. Chlorotrimethylsilane is a very irritative compound, probably due to its very fast hydrolysis to hydrogen chloride. No toxicological data in humans were found in the literature. Severe irritation of skin, eyes (from exposure to the liquid), and mucous membranes (by vapours), and severe burns of mouth and stomach following ingestion were mentioned. In animals, chlorotrimethylsilane caused severe corrosion (burns and blisters) of eyes (cornea, eyelids) and skin. It was highly toxic in a single study in mice but not in rats upon single inhalation exposure. Chlorotrimethylsilane had no genotoxic properties in bacteria and yeast in vitro. In mouse lymphoma cells, it did not cause gene mutations, SCEs, or DNA damage, but showed some weak potential for inducing chromosome aberrations. An in vivo chromosome aberration test in bone marrow of rats was negative at single intra-peritoneal doses up to 74 mg/kg body weight. Hexamethyldisiloxane, a hydrolysis product of chlorotrimethylsilane, showed similar results in these tests. Hydrogen chloride, the other hydrolysis product and included in the in vitro tests as well, was negative in all these tests. There are no data from repeated dose toxicity studies (including reproduction toxicity and carcinogenicity). In a very sensitive model (i.e. lung tumour response in A/He mice), chlorotrimethylsilane increased both the incidence and the multiplicity of lung tumours, but at the maximum tolerated dose only. The relevance of the results is unclear.