Once you know what the chemical is, you could go to the Pesticide safey
Directorates web site which lists all approved chemicals and there
uses, as listed in the Blue book - the annual book covering all these
things.
The address is https://secure.pesticides.gov.uk/pestreg/default.asp
select the first option -products by features, then you can enter the
chemicals active ingredient. Just click the search, adding too much
info can throw no results, where there are some.
Clifford
Bawtry, Doncaster, South Yorkshire