Welding Ventilation, Toxic Metals, and Coated Surfaces
"Welding Ventilation, Toxic Metals, and Coated Surfaces" is lesson 3 of 6 in the Welding (C-60) Learning Hub. It opens with "Two Sets of Rules With Nearly Identical Wording" and works through 5 short steps, then a worked example you can check yourself against.
One-time purchase, no subscription. Law & Business included.
Steps in this lesson
Two Sets of Rules With Nearly Identical Wording
Indoors, Local Exhaust Comes First
Toxic Base Metals, Fluxes, and Coatings in Enclosed Spaces
Coatings: Test First, Then Strip 4 Inches
Four Things Never to Do
The worked example in the course applies this lesson to a realistic job in 5 steps, from "Welding galvanized hanger brackets inside the enclosed room" through "A beam has a coating that gives off toxic fume when heated".
What you'll be able to do
Explain the main idea of "Welding Ventilation, Toxic Metals, and Coated Surfaces" in plain language you can use on the exam.
Apply this step with confidence: "Toxic Base Metals, Fluxes, and Coatings in Enclosed Spaces".
Apply this step with confidence: "Coatings: Test First, Then Strip 4 Inches".
Apply this step with confidence: "Four Things Never to Do".
Test yourself on the worked example and the quick-check quiz inside the classroom.
The diagram for this lesson, exactly as it appears in the Learning Hub.
The first steps of this lesson
Step 1: Two Sets of Rules With Nearly Identical Wording
Welding on a construction site falls under the Construction Safety Orders: 8 CCR Section 1536, "Ventilation Requirements for Welding, Brazing, and Cutting," and Section 1537, "Welding, Cutting, and Heating of Coated Metals." Welding in a fixed shop falls under the General Industry Safety Orders: Section 5150, "Ventilation and Personal Protective Equipment Requirements for Welding, Brazing and Cutting." Both point to the exposure limits in Section 5155 (see the TWA lesson). Know which one governs your job, and use the right section number.
Step 2: Indoors, Local Exhaust Comes First
Section 1536(a) and Section 5150(a) say indoor welding shall use local exhaust systems providing a minimum air velocity of 100 lineal feet per minute in the welding zone. If local exhaust is not feasible, (a)(1) requires mechanical dilution ventilation sufficient to keep exposure below the Section 5155 limits. If neither is feasible, (a)(2) requires respiratory protective equipment. Only the shop rule, Section 5150(a)(3), adds that when workplace monitoring records clearly show the Section 5155 levels are not exceeded, neither mechanical ventilation nor respirators are required.
The remaining 3 steps, the worked example and the quiz are in the course. This is a preview. The full lesson, with the step-by-step explanations, a worked example and a quick-check quiz, is inside the classroom.
Independent exam preparation. Contractors Classroom is not affiliated with the Contractors State License Board, and no course can guarantee a passing result.
