Posted By Robert. Are you sure it's not for carbonmonoxide fumes? Are the hammers really powered by petrol?? If not, is it a generator and is it in a well vented place? Move the power source to a well vented area and use longer extension leads. (110v) Anyway, to answer your question. Check the Arco catalogue. I beleive 3MMM do a disposable type for hydrocarbon vapours which has a long wear period. They are vacuum packed individually.