(1) Manufacturer's instructions. In the use of cleaning materials, because of their possible toxicity of flammability, you must follow appropriate precautions such as manufacturer's instructions.

(2) Degreasing. You must locate degreasing or other cleaning operations involving chlorinated hydrocarbons so that no vapors from these operations will reach or be drawn into the atmosphere surrounding any welding operation. In addition, trichloroethylene and perchlorethylene should be kept out of atmospheres penetrated by the ultraviolet radiation of gas-shielded welding operations.