Choosing the right chemical protective clothing for the job
No chemical protective clothing (CPC) can protect against all levels of chemical risk due to different exposure scenarios, the chemical properties, different type of barriers (fabrics and coating available) and other aspects such as mechanical resistance and the comfort of the wearer.
Standards play a huge role in helping the user select the right garment for protection. Standards set minimum specifications of protective clothing, build a hierarchy through protection level, a level of quality, comparability of products and the selection of the right PPE based on risk assessment.
Overview about CPC standards
The US government regulation that covers US employers’ responsibilities regarding all forms of personal protective equipment (PPE) for use by their employees is 29 CFR 1910.132 (PPE General Requirements). This regulation requires the employer to assess the workplace to determine if hazards are present, or are likely to be present. If yes, then the employer must select, and have each affected employee use, the appropriate type of PPE. “Appropriate” means that the PPE will protect the affected employee from the hazards identified in the hazard assessment.
Except PPE for respiratory protection, the US government does not specify how PPE must perform. Most performance standards in the US are non-mandatory for PPE suppliers to follow. The 29 CFR 1910.120 (Hazardous Waste Operations and Emergency Response) regulation specifically applies to employees who are exposed or potentially exposed to hazardous substances, including hazardous waste, and who are engaged in specific operations.
The OSHA Technical Manual (Section VIII: Chapter 1; Part C) describes four levels of protection based on both the respiratory and skin hazards. The design requirements for the four levels are summarised in Table 2.
NOTE: CPC are categorised from high to low, Level A-D. IDLH (Immediately Dangerous to Life or Health), APR (Air Purifying Respirator), PAPR (Powered Air Purifying Respirator).
EN 14325 provides all the references to the test methods and the classification for all the EN CPC types covering both the mechanical and chemical requirements. All CPC must meet minimum performance requirements.
Various CPC Type standards set higher minimum performance requirements than EN 14325, and they contain the Type specific requirements for design, garment tests, product marking and instructions for use. CPC can easily be recognised by being marked with the symbol, and the CPC marking will provide further information on Type(s) (Type 1 [gas tight], Type 2 [Non-gas-tight], Type 3 [Jet-tight], Type 4 [spray-tight], Type 5 [airborne solid particulates], Type 6 [mist-tight]), name and publication date of the Type standard(s), name and trade mark, identification of manufacturer, size range, potentially the date of manufacture and other pictograms such as reader instructions for use and any other information provided by the manufacturer on the risks against which the CPC protects, chemical products (including name and approx. concentration) that have been tested and the results or where the information can be obtained, other performance levels (eg, mechanical), expected shelf life, and finally information on size, donning and doffing, use and storage, and limitation of uses.
The most common ISO and CEN CPC standards refer to six basic types of protective clothing against chemicals plus additional standards related to infective agents. Under ISO, there are two product standards — ISO 16602 and ISO 17723-1 (still in draft) — that cover: for the first standard, the industrial/professional and consumer applications, and the second the Emergency Teams. There are number of differences between the ISO 16602 and currently revised EN 14325 requirement for the 6 garment Types.
Outlook for future ISO and EN standards
Although at a preliminary stage, there is an effort to merge the EN and ISO standards related to chemical garment PPE, to realign them and better explain the protection levels for end users. The intent is to create a modular approach that would add to the “Type 1 through Type 6” designations to provide a greater explanation of the protections levels through a new way of garment marking.
Overview about selection of CPC — a life saving choice
The selection of chemical protective clothing (CPC) is a step-by-step approach that starts with a broad risk assessment for a defined work situation. The main purpose of the hazard and risk assessment is to identify and then to eliminate or minimise the worker exposure to residual hazards and risk.
A risk assessment is a combination of likelihood of accidents (never, unlikely, possible, likely, multiple exposures likely, continuous) and severity of consequence (no effect, discomfort, treatable injury, debilitating injury, death).
The first step in a risk assessment is usually to follow the process or understand the specific work location in which the exposure(s) may occur. The exposure is defined by duration (eg, seconds, hours), frequency (eg, continual, intermittent or accidental contact), amount and the force of the exposure, and the direction of the exposure (to which part of the body). Before PPE is chosen, all risk mitigation and engineering and administrative controls should be applied.
There should be a consideration of chemical risk. Is it a gas, vapour, liquid, particulate? Can the chemical change physical status (eg, from liquid to vapour)? Many of the key properties of a specific chemical that are important to CPC selection can be found in the safety data sheet (SDS). Knowing the toxicity or consequences of short- or long-term exposure to the hazard is essential. Data of garments’ fabric, seams and closure system on penetration and permeation testing will indicate the permitted time of exposure before reaching human toxicity.
The CPC, as the last line of defence, must not be the weakest link in protecting the worker. Therefore, during the selection, the purchaser should ask for as many details as possible on the CPC being considered.
The focus is going to be skin contact as CPC is intended to protect parts of the skin. In case of a mist, gas or particulates, the imperviousness of the CPC becomes important as it may become part of an assembly of PPE (eyes, face, respiratory protection). The direction and the intensity of the exposure, if it is a mist, spray or jet, are important to know when choosing the CPC, and finally, the duration of potential exposure to the chemical(s) — see Flowchart 1.
All of the content in this paper is a summary of the technical paper SP: Current global standards for Chemical Protective Clothing: How to choose the right protection for the right job? written by Eric Van Wely (Chair of ISO TC94 SC13 sub-committee on Protective Clothing).
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