I looked it up in the Oxford English Dictionary (via my local public library).
greenwash
verb, transitive. (a) To mislead (the public) or counter (public or media concerns) by falsely representing a person, company, product, etc., as being environmentally responsible; (b) to misrepresent (a company, its operations, etc.) as environmentally responsible.
The earliest source the OED found was in 1989, in The Daily Telegraph (London).
greenwash
verb, transitive. (a) To mislead (the public) or counter (public or media concerns) by falsely representing a person, company, product, etc., as being environmentally responsible; (b) to misrepresent (a company, its operations, etc.) as environmentally responsible.
The earliest source the OED found was in 1989, in The Daily Telegraph (London).