chemical products for use in tracing cracks, fissures, defects, and stains in and on surfaces; namely, penetrants, dyes, developers, solvents, and penetrant removers, all of which may be in the form of gases, sprays, aerosol sprays, suspensions, emulsions, powders or solids

Chemical Preparations for Use in the Detection of Fissures, Defects, Cracks and Flaws in Metal Surfaces