Chemical protective clothing explained

Chemical protective clothing (CPC) is clothing worn to shield those who work with chemicals from the effects of chemical hazards that can cause injuries on the job. It provides a last line of defense for chemical safety; it does not replace more proactive measures like engineering controls.^[1]

Clothing selection factors

There are some considerations with chemical protective clothing. For instance, no clothing is "impervious," since all clothing will eventually seep in chemicals. CPC also prevents evaporation, causing skin temperature to increase and potentially increasing the permeability of skin. CPC that has not been tested for the specific operating condition it is used in may not provide adequate protection. The same material, even at the same thickness, may provide different levels of protection depending on the manufacturer, since different manufacturers use different processes and may add different additives. Finally, while the test data will provide information on individual chemicals based on "worst-case scenario" continuous contact testing, most industrial exposures are not continuous and are in fact mixtures of chemical, for which permeation rates are different.

When selecting Chemical Protective Clothing, there are several factors that must be taken into account prior to selecting the garments that are needed. A risk assessment is often conducted to assist with making sure that the right protective clothing is selected. When selecting the appropriate chemical protective clothing, it is recommended to determine:^[2]

The chemicals being used and their hazards
The state of those chemicals; for example, if they are vaporous, they could be more hazardous
Whether contact is a result of occasional splashing or a result of more continuous contact
Whether the worker can be exposed from handling contaminated CPC
Environmental Conditions (Weather, location)
Duration the worker will be wearing the protective clothing
The room temperature where the chemical is being handled
The parts of the body that the chemical could potentially contact
Whether the CPC resists physical wear and tear commensurate with the type of work being done
Whether the CPC interferes with the work, for instance by limiting dexterity

From there, it is recommended that candidate garments should be selected and subject to appropriate testing. Testing is also considered necessary to make sure the material is suitable to the specific condition it will be used in, as opposed to the generic, worst-case scenarios it ordinarily undergoes. Once a garment is selected, it should undergo a limited evaluation with worker training. Once the garment is regularly used it should be regularly evaluated.

Clothing ensemble

Chemical Protective Clothing ensembles are not a one size fits all approach. The level of protection needed and the hazards that are associated with the chemical will play a major role in what pieces of the ensemble are needed to fully protect the worker. When purchasing Chemical Protective Clothing, careful consideration should be taken to make sure that all pieces of the ensemble are compatible with each other. Pieces of the ensemble may include:^[3]

Protective Suit (Fully Encapsulating, Splash Suit)
Respiratory Protection (Self Contained Breathing Apparatus, Respirator)
Head Protection (Helmet)
Hearing Protection (Ear Plugs)
Eye Protection (Safety Goggles / Face Shield)
Gloves (Inner and Outer)
Boots

Gloves

When using solvents, an improper glove selection may allow the solvent to leak through the gloves leading to skin contact. Appropriate gloves protect workers from hazards such as burns, cuts, electrical shocks, amputation, and chemical absorption or contact. Improper selection of gloves gives employees a false sense of security since chemicals can penetrate the "protection" without showing any signs of failure. ^[4]

There are standards that protective gloves have to meet, and manufacturers' data should be used in selecting appropriate fabric properties. They cannot just be any fabric, examples of fabric that should not be used are nylon, polyester, leather, neoprene, or latex. Appropriate properties to look for the chemical resistance, thermal protection, cut and puncture resistance, and non-electrical conductivity. When working with chemicals workers should have the ability to remove gloves and protective clothing in a simple way that avoids skin or other contamination to themselves or others. Protective gloves should be sized properly to prevent restricted worker movement or tearing when working with different types of materials.

Chemical-resistant gloves can be made of different kinds of rubber or plastics. These materials can be laminated or blended to create a better performance. Thicker gloves improve the protection but may be clumsier to use, which can reduce safety.^[5]

Examples of chemical-resistant gloves:

Butyl gloves: Made of synthetic rubber, resistant to oxidation, ozone corrosion, and abrasion. Does not perform well with aliphatic or aromatic hydrocarbons and halogenated solvents. Protects against a wide variety of dangerous chemicals.
Natural latex rubber gloves: One of the most popular general-purpose gloves, mainly because of comfortability. Have a great tensile strength, which helps against abrasions that can be caused by grinding and polishing of materials. Protect from most water solutions of acids, alkalis, salts, and ketones. There are people who are allergic to latex, which causes irritation and is not suitable for all employees. Great alternatives that can be offered to employees are hypoallergenic gloves, glove liners, and powderless gloves.
Neoprene gloves: Made of synthetic rubber which helps with dexterity, has a higher density, and good tear resistance. Able to protect against many fluids like hydraulic, gasoline, certain alcohols, organic acids, and alkalis.
Nitrile gloves: Made of copolymer, due to those properties it provides protection from chlorinated solvents. After prolonged exposure to substances that cause other brands of gloves to deteriorate, nitrile gloves stand heavy. Not recommended for use with strong oxidizing agents, aromatic solvents, ketones, and acetates. Offer good protection when working with oils, greases, acids, and alcohols.

Levels of protection

The EPA categorizes Chemical Protective Clothing into four levels, with Level A being the highest level of protection and Level D being the lowest level of protection. These levels are based on the amount of protection for the user’s skin and respiratory protection.^[6]

Level A – The highest level of both respiratory and skin protection. Consists of a full encapsulating suit that is vapor tight with respiratory protection consisting of either Self Contained Breathing Apparatus (SCBA) or supplied air respirator. Used when protection from vapor and liquid is needed. Ensemble may also consist of internal radio communication, head protection, boots, and gloves.
Level B – The highest level of respiratory protection with reduced skin protection. Consists of chemical resistant clothing that may or may not be fully encapsulating, paired with either a Self Contained Breathing Apparatus (SCBA) or supplied air respirator. Used when there is a reduced risk of vapor exposure but there are concerns with exposure to respiratory tract. Ensemble may also consist of radio communication, head protection, face shield, boots, and gloves.
Level C – Reduced respiratory protection along with reduced skin protection. Consists of a liquid splash protection suit (coveralls) paired with an air purifying respirator. Used when there is reduced risk of skin exposure to chemicals but there are concerns with contaminants in the air. Ensemble may also consist of radio communication, head protection, face shield, boots, and gloves.
Level D – The lowest level of protection required. Can be used where there is no chance of chemical being splashed onto the worker and there are no contaminants that would harm the respiratory tract. Ensemble consist of standard work coveralls, face shield or safety glasses, gloves, and boots.

NFPA standards

Over the years, the roles and responsibilities of first responders has drastically changed. To protect the best interest of those first responders, standards have been developed to assist agencies with selecting the appropriate level of protection. These standards also ensure that the chemical protective clothing has been tested and certified to meet a minimum set of specifications. The standards not only cover the protective clothing suit, but also all other components such as respiratory protection, gloves, boots, and all other garments that complete the ensemble.^[7]

NFPA 1991 standard covers the requirements for ensembles that offer the highest level of protection. These types of suits would be classified on the EPA scale as Level A suits. These types of suits are fully encapsulating and are air tight (vapor resistive).
NFPA 1992 standard covers the requirements for ensembles that are liquid/splash protective. These types of suits would be classified on the EPA scale as Level B suits. These suits are resistive to liquids and are not rated for any type of vapor protection.
NFPA 1994 standard is broken down into 4 classes. NFPA 1994 Class 1 and 2 are intended to protect the user in an environment that requires a self contained breathing apparatus and where vapors or liquids are expected to make contact with the users skin. These liquids or vapors may include those of chemical warfare, bloodborne pathogens, or industrial chemicals. NFPA 1994 Class 3 must also be rated to protect the user from the same potential exposures of Class 1 and 2, however these ensembles only require the use of air purifying respirator. NFPA 1994 Class 4 ensembles are rated to protect the user from bloodborne pathogens and biological agents and offer no protection against industrial chemicals or chemical warfare. Class 4 ensembles are rated to be used with an air purifying respirators as well.
NFPA 1999 standard covers the requirements for ensembles that are single use or multi-use for protection against bloodborne pathogens or potential exposures to infectious diseases. These ensembles are rated to be used with an air purifying respirator.

Notes and References

CDC - NIOSH Publications and Products - A Guide for Evaluating the Performance of Chemical Protective Clothing (90-109). www.cdc.gov. 1990 . 10.26616/NIOSHPUB90109 . 2027/mdp.39015041531511 . 2016-07-15. free.
VAN WELY. Eric. November 2017. Current global standards for chemical protective clothing: how to choose the right protection for the right job?. Industrial Health. 55. 6. 485–499. 10.2486/indhealth.2017-0124. 0019-8366. 5718769. 29046493.
Web site: OSHA Technical Manual (OTM) - Section VIII: Chapter 1 Occupational Safety and Health Administration. 2021-11-06. www.osha.gov.
Web site: Hand and Body Protection . March 11, 2024 . OSHA.
Book: OSHA Glove Selection Chart . Florida State University . 1 . English . April 6, 2024.
Web site: US EPA. OLEM. 2013-05-17. Personal Protective Equipment. 2021-11-07. www.epa.gov. en.
Stull, J. O., Stull, G. C., & Baxter, C. M. (2018, April). Risk-Based Selection of Chemical Protective Clothing. National Fire Protection Administration. Retrieved 11 6, 2021, from https://www.nfpa.org/-/media/Files/white-papers/WhitePaperRiskBasedSelectionOfChemicalProtectiveClothing.pdf