Which safety precaution is not required when handling penetrant materials?

When handling penetrant materials, specific safety precautions are vital to prevent inhalation, skin contact, and other potential hazards. Utilizing basic safety equipment typically includes items such as gloves and goggles, as these directly protect the skin and eyes from chemical exposure. Wearing complete protective clothing further enhances this protection by covering more body areas, which is crucial when dealing with potentially hazardous substances.

Air-line respirators, while beneficial in certain environments, are not universally necessary for handling penetrant materials. These materials may not produce airborne contaminants at levels requiring such respiratory protection, especially in situations where proper ventilation is available. The use of basic safety equipment combined with personal protective equipment tailored to the specific material and work environment can sufficiently mitigate risks in many cases.

Therefore, air-line respirators do not always constitute a requirement, particularly if the conditions suggest that the hazards can be managed through other means. Thus, the precaution that is not strictly required when handling penetrant materials is the use of air-line respirators.