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This website publishes administrative rules on their effective dates, as designated by the adopting state agencies, colleges, and universities.

Rule 4123:1-5-18 | Control of air contaminants.


(A) Reserved.

(B) Reserved.

(C) Where employees are exposed to hazardous concentrations of air contaminants, the air contaminants will be minimized by at least one of the following methods:

(1) Substitute a non-hazardous, or less hazardous material;

(2) Confine or isolate the contaminants;

(3) Remove at or near source;

(4) Dilution ventilation;

(5) Exhaust ventilation;

(6) Using wet methods to allay dusts. Note: Good housekeeping is of definite value in minimizing air contaminants created by dusts.

(D) Exhaust systems: machinery and equipment.

(1) Grinding, polishing and buffing.

(a) Abrasive wheels and belts.

(i) Abrasive wheels and belts will be hooded and exhausted when there is a hazardous concentration of air contaminants.

(ii) This does not apply to abrasive wheels or belts:

(a) Upon which water, oil, or other liquid substance is used at the point of the grinding contact; or

(b) To small abrasive wheels used occasionally for tool grinding.

(b) Separate exhaust systems.

Abrasive wheel and buffing wheel exhaust systems will be separate when the dust from the buffing wheel is of flammable material.

(2) Generation of toxic materials.

When toxic materials are generated in hazardous concentrations during their application, drying, or handling, they will be minimized or eliminated by at least one of the methods described in paragraph (C) of this rule.

(3) Internal combustion engines.

Hazardous concentrations of air contaminants produced by internal combustion engines will be exhausted.

(E) Exhaust systems - structural specifications.

(1) Exhaust or ventilating fan.

Each exhaust or ventilating fan located less than seven feet above the floor or normal working level will be guarded.

(2) Ductwork.

Exhaust ductwork will be sized in accordance with good design practice which will include consideration of fan capacity, length of duct, number of turns and elbows, variation in size, volume, and character of materials being exhausted.

(3) Discharge.

The outlet from every separator or (collector) will discharge the air contaminants collected by the exhaust system, in such manner that the discharged materials will not re-enter the working area in hazardous concentrations.

(4) Location of air supply openings or inlets.

Air supply openings or inlets through which air enters the building or room in which the local exhaust system is in operation will be isolated from any known source of contamination from outside of the building.

Last updated September 1, 2023 at 9:24 AM

Supplemental Information

Authorized By: 4121.12, 4121.121, 4121.13
Amplifies: 4121.47
Five Year Review Date: 11/1/2026
Prior Effective Dates: 4/1/1964, 8/1/1977, 1/1/1986, 4/10/2011, 6/1/2016