Document 6XKozKmV3m5KkOMe3g9QJkQ1

PERSONAL PROTECTIVE EQUIPMENT esses also emit ultraviolet radiations Cas welding presents problems mostly in the control of infrared and visible radiations. Heavy amperage arc welding also presents problems in the control of ultraviolet Welders may choose the shade of lenses they prefer within one or two shade num bers Following are shades commonly used SHADES no 1 5 to no 3 0 are intended for glare from snow, ice, and reflecting sur faces, and for stray flashes and reflected radiation from cutting and welding op erations in the immediate vicinity (for goggles or spectacles with side shields worn under helmets in arc welding op erations, particularly gas shielded arc welding operations) shade no 4, the same as shades 1 5 to 3 0, but for greater radiation intensity For welding, cutting, brazing, or solder ing operations, the guide for the selection of the proper shade numbers of filter lenses or windows in Chapter 29, "Welding and Cut ting," should be used (Recommendations are also in the American Standard Safety Code for Head, Eye, and Respiratory Protec tion, 22 1-1959 ) To protect filter lenses against pitting, they should be worn with a replaceable plas tic or glass cover plate For protection against visible glare only, safety spectacles having mild filter shade lenses or polarizing lenses and having opaque side shields are adequate For con ditions where hot metal may spatter and visible glare must be reduced, a plastic face shield worn over mild filter shade specta cles with opaque side shields should be specified It is permissible and often desirable to combine the shade of the plate in the weld er's helmet with the shade of the goggle or spectacle worn underneath the helmet in order to produce the desired total shade. This has the advantage of providing some protection to the eyes from other welding operations or from an accidental arc when the helmet is raised for inspection. To protect against ultraviolet and infra red radiation, as well as against visible glare, protective lenses should be installed in a hand shield or welder's helmet The shield should he made of a nonflammable material opaque to the dangerous radiation and a poor conductor of heat A metal shield is not desirable, for it heats under infrared radiation Some tinted lenses used m special work afford no protection from infrared and ul traviolet radiations For instance, most fly 36-10 Various filter lens shades 36-29