Subchapter 7. General Industry Safety Orders
Group 16. Control of Hazardous Substances
Article 107. Dusts, Fumes, Mists, Vapors and Gases

§5150. Ventilation and Personal Protective Equipment Requirements for Welding, Brazing and Cutting.

(a) Mechanical Ventilation for Indoor Operations. Local exhaust systems providing a minimum air velocity of 100 lineal feet per minute in the welding zone shall be used except as otherwise specified by this Section.

(1) Where local exhaust ventilation is not feasible, mechanical dilution ventilation sufficient to prevent exposures to concentrations of airborne contaminants from exceeding those specified in Section 5155 shall be provided.

(2) Respiratory protective equipment, in accordance with Section 5144, shall be used when the methods described in paragraphs (a) and (a)(1) above are not feasible.

(3) Where workplace monitoring records clearly demonstrate that exposure levels specified in Section 5155 are not exceeded, neither mechanical ventilation nor respiratory protective equipment is required.

NOTE: Where workplace monitoring has demonstrated that exposure levels are not exceeded under the worst conditions, then the same data may be used under more favorable conditions.

(b) Toxic Substances Used in Any Enclosed Space.

(1) Local exhaust ventilation shall be used when potentially hazardous materials are employed as base metals, fluxes, coatings, platings or filler metals. These include, but are not limited to, the following materials:

(A) Beryllium

(B) Cadmium

(C) Chromium

(D) Fluorides

(E) Lead

(F) Mercury

(G) Zinc

(H) Inert-gas metal-arc welding or oxygen cutting of stainless steel

(2) The exhaust system shall be vented in a manner such that workers and others are not exposed to hazardous concentrations of toxic substances.

(3) When the nature of the work is such that local exhaust ventilation is not an effective means for preventing potentially hazardous exposure levels, as specified by Section 5155, supplied-air respirators shall be worn.

(c) Toxic Substances Used in the Open Air. Where toxic substances such as those listed in paragraph (b)(1) are used, respiratory protective equipment, in accordance with Section 5144, shall be provided except as otherwise specified by this subsection.

(1) In operations involving beryllium-containing base or filler metals, only supplied-air respirators shall be used.

(2) Except for operations involving beryllium, cadmium, lead or mercury, respiratory protective equipment is not required when natural or mechanical ventilation is sufficient to remove welding fumes from the breathing zone of the workers.

(d) Improper Use of Welding Gases. Compressed gases used for welding and cutting shall not be used for ventilation purposes, comfort cooling, blowing dust from clothing, or cleaning the work area.

(e) Chlorinated Hydrocarbons. Degreasing or other operations involving chlorinated hydrocarbons shall be located or controlled such that vapors from these operations will not enter the atmosphere surrounding any welding or cutting operations to prevent the degradation of such chlorinated hydrocarbon vapors to more highly toxic gases by the action of heat or ultraviolet radiation.

(f) Precautionary Labels. Hazardous materials used in welding and cutting shall bear precautionary labels as described by this subsection. Any label may be used which describes the hazards of and lists the precautionary measures for a hazardous material in a manner equivalent to that included in this subsection.

(1) All filler metals and fusible granular materials shall carry the following notice, as a minimum, on tags, boxes or other containers:

CAUTION

Welding may produce fumes and gases hazardous to health. Avoid breathing these fumes and gases. Use adequate ventilation.

(2) Filler metals containing cadmium and cadmium-plated materials shall carry the following notice on tags, boxes or other containers:

WARNING

CONTAINS CADMIUM. POISONOUS FUMES MAY BE FORMED ON HEATING.

Do not breathe fumes. Use only with adequate ventilation such as fume collectors, exhaust ventilators, or supplied-air respirators. If chest pain, cough, or fever develops after use, call physician immediately.

NOTE: The intent of calling a physician is to provide immediate medical services.

(3) Containers of fluoride fluxes shall bear the following statement:

CAUTION

CONTAINS FLUORIDES

This flux when heated gives off fumes that may irritate eyes, nose, and throat.

1. Avoid fumes--use only in well-ventilated spaces.

2. Avoid contact of flux with eyes or skin.

3. Do not take internally. (Title 24, T8-5150(a), (b))

NOTE: Authority cited: Section 142.3, Labor Code.

HISTORY

1. New section filed 7-18-75; effective thirtieth day thereafter (Register 75, No. 29).

2. Amendment filed 7-16-76; effective thirtieth day thereafter (Register 76, No. 29).

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