Any person who, without approval of the chief of the Washington state patrol, through the director of fire protection, sells or offers for sale in Washington any fire hose, fire engine or other equipment for fire protection purposes which is fitted or equipped with other than the standard thread is guilty of a misdemeanor: PROVIDED, That fire equipment for special purposes, research, programs, forest firefighting, or special features of fire protection equipment found appropriate for uniformity within a particular protection area may be specifically exempted from this requirement by order of the chief of the Washington state patrol, through the director of fire protection.