Peracetic acid, also known as peroxyacetic acid or PAA, is used in numerous applications, including as a chemical disinfectant in healthcare, sanitizer in the food industry, and purifier during water treatment. It’s an often preferred cleaning agent because it leaves no toxic residue and it is no-rinse.
Given PAA’s increasing popularity and use throughout multiple industries, more attention is now being focused on health hazards and associated risks when PAA is used in the workplace. Moreover, peracetic acid’s ability to become airborne, the varying concentrations that may be used, and the relatively low occupational exposure limits (OELs) mean that if you are going to use PAA, there is an increased need to review company risk assessment procedures and personal protective equipment (PPE) choices for various applications of this substance.
Here, we will take a deeper dive into what peracetic acid is, the hazards employees may face if exposed to it, and controls employers can consider taking to help protect employees. By way of example, we will look at the pharmaceutical and food safety industries where PAA is more commonly being used.
Tell Me More About Peracetic Acid, the Hazards and Health Effects
PAA is an organic compound produced by reacting acetic acid, a component of vinegar, and hydrogen peroxide. This creates an equilibrium mixture of acetic acid, hydrogen peroxide, and peracetic acid. The vapor above a peracetic acid solution contains all three of these compounds.
Peracetic acid is a strong oxidizer and a highly reactive, unstable, volatile peroxide-based molecule for which there is currently no NIOSH recommended exposure limit (REL) or OSHA permissible exposure limit (PEL). However, there are other established exposure limit values for peracetic acid, which include:
- American Conference of Governmental Industrial Hygienists (ACGIH) has published a threshold limit value–short-term exposure limit (TLV-STEL) of 0.4 ppm (1.24 mg/m3)
- EPA’s National Advisory Committee for the Development of Acute Exposure Guideline Levels (AEGLs) for Hazardous Substances has published acute exposure guideline levels (AEGLs)
- NIOSH has proposed 0.64pm (1.7mg/m3) as an immediately dangerous to life and health (IDLH) concentration value, which is currently under review
- The state of California HEAC is considering a PEL of 0.2ppm per 8hr TWA
For more information, please see the technical data bulletin entitled: Worker Personal Protective Equipment (PPE) Tips for Peracetic Acid Use in Pharmaceutical Manufacturing.
In terms of potential health effects, PAA may be corrosive to eyes and skin with direct contact and has some volatility, so worker exposure can occur to airborne aerosol and vapor. EPA’s National Research Council (US) Committee on Acute Exposure Guideline Levels reports “peracetic acid can be corrosive/irritating to the eyes, mucous membranes of the respiratory tract, and skin. It may cause lacrimation (tears), extreme discomfort, and irritation to the upper respiratory tract in humans after exposure to concentrations as low as 15.6 mg/m3 (5 ppm) peracetic acid for only 3 min. ” So, how can employers help protect workers from the hazards associated with PAA?
Hierarchy of Controls
The hazard classification of PAA under the Globally Harmonized System (GHS) will vary depending on the chemical concentration and product formulation of the PAA product being used, but typical disinfectant products may be classified as flammable, oxidizer, toxic, corrosive and hazardous to the environment.
Employers should continue referring to safety data sheets (SDS) for guidance. James M. Boiano, MS, CIH, a senior industrial hygienist and assistant coordinator of the NIOSH Healthcare and Social Assistance Sector Program says, “The OSHA Hazard Communication standard requires that these sheets be available in the workplace to ensure that workers have access to information on the hazards each chemical pose and the proper techniques for handling, storage and transportation. Study this information carefully, then proceed with caution.”
“This would include implementing the hierarchy of controls in the following, decreasing order of efficacy: substitution, engineering controls, following administrative controls, work practice controls, and personal protective equipment (PPE),” Boiano says. “Should workers experience symptoms related to exposure to PAA, they should notify their employer’s health and safety department, occupational health unit, or their doctor so that the work environment is evaluated, and corrective actions can be taken.”
PAA Use in Pharmaceutical and Medical Applications
Peracetic acid is commonly used as a broad-spectrum biocide in medical and industrial applications. It is a powerful oxidizing agent that kills microorganisms by penetrating the cell wall. It is even effective against anthrax spores.
PAA-containing products can have many applications where pharmaceuticals are manufactured, processed, or administered. These activities often are accompanied by cleaning, sanitizing, disinfecting, sterilizing, or neutralizing and PAA-containing products may be chosen by facilities for all these tasks. Increased use of PAA may also occur due to increased public scrutiny and regulatory pressure around contaminated products and worker health.
The nature of these cleaning and disinfecting tasks often means repeatedly using higher PAA concentrations spread over large surface areas, which may result in significant worker exposures. Keep in mind that these EPA-regulated products must be used according to label directions, which can limit potential opportunities for reducing exposure by changing the way a product is used (such as not spraying when the product label indicates to apply using a sprayer or not maintaining a wet surface for the prescribed contact time).
Air monitoring for PAA can be challenging because it is highly reactive, it can quickly degrade, it is commonly found with other components, and the lack of a NIOSH or OSHA validated sampling method. Improvements for monitoring are in demand because of the increased marketplace use of these products and evolving exposure concerns. Qualitative assessments can be performed that are more academic and based on modeling, though that has proven to be challenging. Also, quantitative exposure assessments should be conducted where required.
Air monitoring methods can be divided into two main types: direct-reading where a device can provide results right away, often in real-time as the work tasks are being conducted; and methods that require laboratory analysis, so results are not available until later and typically only represent an average concentration over the time period sampled (Time-Weighted Average or TWA). To learn more about air monitoring methods that can help inform safety decisions, please see the technical data bulletin entitled: Worker Personal Protective Equipment (PPE) Tips for Peracetic Acid Use in Pharmaceutical Manufacturing.
Exposure controls that reduce chances of inhalation should be considered where an employer’s risk assessment indicates that the respiratory hazard may result in unacceptable exposures.
Peracetic Acid Use in the Food and Beverage Processing Industry
PAA-containing products can have many applications where poultry, meat, vegetables, and beverages are processed. These activities often are associated with cleaning, sanitizing, or sterilizing and PAA-containing products may be chosen for all these tasks where appropriate. Increased use of PAA may also be expected due to increased public scrutiny from food recalls and increasing Hazard Analysis Critical Control Point (HACCP) FDA regulatory pressure around contaminated food products.
According to the USDA Food Safety Inspection Service fact sheet, if appropriate controls are not in place, employees may potentially be overexposed to PAA from the following operations in food, meat, or poultry processing facilities:
- Inadequate ventilation: poor local exhaust ventilation on spray cabinets, off-gassing from chillers, inadequate ventilation on the kill floor
- Splashes and overspray from spray cabinet openings and high nozzle pressure, chemical mixing in floor drains, hand application with spray tanks, and discharge of waste solution from cabinets and tanks directly onto the floor
- Failure to properly control solution pH may also contribute
Keep in mind that these EPA and USDA regulated products must be used according to label directions or prescribed concentrations for food quality, which can limit potential opportunities for reducing exposure by changing the way a product is used (such as not spraying when the product label indicates to apply using a sprayer, not maintaining a wet surface for the prescribed contact time or reducing concentrations).
The USDA Food Safety Inspection Service fact sheet also suggests providing proper ventilation, containment, and process controls to reduce employee’s exposure to PAA vapor, mists, and droplets. These controls could include local exhaust ventilation, shielding of spray areas, and dedicated drainage.
How Do You Choose the Right PPE to Help Protect Against PAA?
OSHA, the EPA, and FDA provide guidance about the use of products containing PAA. Employers should thoroughly consult applicable guidance when determining what PPE may be needed based on how workers are exposed to PAA in the workplace. For an overview related to pharmaceutical manufacturing, please review our technical data bulletin entitled: Worker Personal Protective Equipment (PPE) Tips for Peracetic Acid Use in Pharmaceutical Manufacturing.
Respirator manufacturers may also have publications that can help employers with their respirator selection for PAA. Information on the type of respirator recommended (including cartridge and filter if applicable), along with cartridge service life data, should be requested from the supplier to help the employer satisfy the requirements of the OSHA Respiratory Protection Standard (29 CFR 1910.134). See our technical bulletin #185: Respiratory Protection for Hydrogen Peroxide, Peracetic Acid, and Acetic Acid, for more information on respirator products for PAA. Employers may want to consider respiratory protection that includes suitable eye protection such as a full facepiece respirator or a powered air-purifying respirator (PAPR) with appropriate headgear due to the eye irritation potential of PAA-containing products.
Employers should also consider other appropriate PPE for eye and skin protection due to the potentially irritating or corrosive nature of PAA. Tasks that may result in eye or skin contact with liquid require eye and face protection, gloves, and body coverings such as coveralls. Vapor or aerosol presence may require goggles or respiratory protection that includes suitable eye protection. Manufacturer-provided selection guides may be helpful in choosing appropriate eye and skin protection. Keep in mind the nature of the task, including chemical concentration and extent of potential eye and skin contact, when selecting PPE.
https://www.ams.usda.gov/sites/default/files/media/Peracetic%20Acid%20TR%203_3_2016%20Handling%20final.pdf, pg. 12
Pechacek, N. et. al. Evaluation of the toxicity data for peracetic acid in deriving occupational exposure limits: A minire- view. Toxicology Letters 233 (2015) 45-47.
https://www.ncbi.nlm.nih.gov/books/NBK220001/, National Research Council (US) Committee on Acute Exposure Guideline Levels. Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 8. Washington (DC): National Academies Press (US); 2010. 7, Peracetic Acid Acute Exposure Guideline Levels. Available from: https://www.ncbi.nlm.nih.gov/books/NBK220001/