Permissible exposure limit respiratory protection

Occupational Safety and Health Administration (OSHA) has not identified thresholds for carcinogens that will protect 100% of the population. It usually recommends that occupational exposures to carcinogens be limited to the lowest detectable concentration. To ensure maximum protection from carcinogens through the use of respiratory protection, only the most reliable and protective respirators are recommended. The OSHA permissible exposure limit (PEL) for benzene-soluble fraction of coke oven emissions is 0.150 mg m. ... 

In 1996, there were 25,000 workers employed in 75-100 domestic wood treatment plants using coal tar creosote. As a result of the use of engineering controls and personal protective equipment (e.g., respiratory protection and impervious gloves) required in the 1986 settlement of the EPA Special Review process,1 airborne exposures to creosote components in the workplace are generally below the OSHA permissible exposure limit (PEL) of 0.2 mg benzene soluble particulates perm3 air (Rivers 1990). 

The selection of respirator is based on the nature of respiratory hazards such as permissible exposure limits, established concentration immediately dangerous to life, actual concentration of hazardous substances, and amount of oxygen. When using filters, the ambient air must contain at least 20% oxygen at sea level. Filter protection should not be used for unknown contaminants and contaminants fliat are immediately dangerous to life and health. 

The product of the protection factor of the respiratory protection equipment and the permissible exposure limit (PEL). 

PEL OSHA Permissible exposure limit—Limit based on 8 h TWAs. Exposures below the PEL do not require respiratory protection. 

General respiratory protection requirements begin at 29 CFR 1926.55 — Gases, vapors, fumes, dusts, and mists. Employees exposed to any material or substance at a concentration above the permissible exposure limit (PEL) specified in Appendix A to 1926.55 must be avoided. Comphance must be achieved by using administrative (i.e., employee shift changes) or engineering (i.e., ventilation) controls first. When these controls are not feasible to achieve fiill compliance, protective equipment must be used to keep the exposure within the PELs prescribed. 

To understand the proper level of respiratory protection, you must conduct a hazard assessment to define your potential workplace exposures. This assessment will define if the hazards are Immediately Dangerous to Life and Health (IDLH) or non-IDLH. This is critical information needed to define whether an air-purifying respirator (APR) is suitable or if an air supplied respirator is required. The National Institute for Occupational Safety and Health (NIOSH) Pocket Guide to Chemical Hazards (www.cdc. gov/niosh/npg/) is a comprehensive resource that will define IDLH levels for most hazards you will encounter. The Pocket Guide will also define specific characteristics of your hazard of concern as well as provide the NIOSH Recommended Exposure Limit (REL) and OSHA Permissible Exposure Limit (PEL). 

Wherever feasible engineering and work practice controls which can be instituted immediately are not sufficient to reduce exposures to at or below the permissible exposure limit, they shall nonetheless be used to reduce exposures to the lowest practicable level, and shall be supplemented by respiratory protection in accordance with paragraph (g) of this section. A program shall be established and implemented to reduce exposures to at or below the permissible exposure limit, or to the greatest extent feasible, solely by means of engineering and work practice controls, as soon as feasible. 

Where control methods do not reduce silica exposures to OSHA s permissible exposure limit, respirators are required, and employers must have a written respiratory protection program in accord with OSHA s Respiratory Protection standard. It must include the following ... 

The employer shall implement engineering and work practice controls, including administrative controls, to reduce and maintain employee exposure to lead to or below the permissible exposure limit to the extent that such controls are feasible. Wherever all feasible engineering and work practices controls that can be instituted are not sufficient to reduce employee exposure to or below the permissible exposure limit prescribed in paragraph (c) of this section, the employer shall nonetheless use them to reduce employee exposure to the lowest feasible level and shall supplement them by the use of respiratory protection that complies with the requirements of paragraph (f) of this section. 

Employers are required to develop and implement a written respirator program if respirators are being worn or if the permissible exposure limits (PELs) exceed those required by OSHA.. OSHA s 1910.134 respiratory protection standards require the following components. 

Air Contaminants (29 CFR 1910.1000). OSHA requires that employees who must work in or near industrial operational areas with an ambient air exposure limit above a set level wear appropriate respiratory protection. The permissible exposure levels (PELs) of major concern for colorant and additive formulators are as follows ... 

Toxic conditions. Personal protecdve equipment requirements (including respiratory protection) are based in pan on the concentration of toxic vapor or gas in the air. A toxic atmosphere is defined (by OSHA) as having a concentration which exceeds permissible or published exposure limits (such as the TLV or PEL)... 

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