Hydrofluoric glass workers

Employees should be informed of the risks of exposure to corrosive agents and be well trained to handle the chemicals as well as to act when they have been exposed. Showers for rapid irrigation with water should be easily accessible. A 1% copper sulfate solution, polyethylene glycol 300 or 400, 5% sodium thiosulfate solution, and a proper calcium preparation should be present in the first-aid kit. A calcium preparation for topical treatment should also be present near any employees work site where hydrofluoric acid or fluorides are used. Workers at risk should wear proper protective equipment, which may include eye glasses, face masks, gloves, boots, and safety dresses. 

Arsenic occurs in seawater in a variety of chemical species, the most abundant of which are arsenate, arsenite, methylarsonate and dimethylarsinate Andreae, 1979 Cullen and Reimer, 1989). The method described here permits the individual determination of these four species. It provides high sensitivity (limit of detection 4.0pmol/L) and adequate precision (5-10 % relative standard deviation). In seawater and most natural waters, interferences are absent or minimal. This method was first published by Andreae (1977) and has been modified subsequently Andreae, 1983). It has been used successfully by numerous workers, often with minor modifications. Some improvements have been proposed recently, such as the addition of cysteine to the reaction mixture Le et al, 1994 Howard and Salou, 1996) and the use of glass beads etched with hydrofluoric acid in the cold trap Howard and Comber, 1992).The following description represents the procedure followed in the author s laboratory. 

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