When gas welding or burning welders are required to wear tinted goggles or weldin hoods with a filter lens of not less than what shade?

When gas welding or burning, welders are required to wear tinted goggles or welding hoods with a filter lens of not less than shade 4. This shade provides adequate protection against the intense light and ultraviolet radiation generated during the welding process. For more intense welding operations, higher shade numbers may be necessary. Always refer to specific safety guidelines and regulations for the type of welding being performed.