Standard Guide for Per- and Polyfluoroalkyl Substances Site Screening and Initial Characterization

Importancia y uso:

4.1 PFAS are widely used in commercial and industrial applications worldwide (see Fig. 1). PFAS are of concern due to their documented persistence and their studied impacts on human health and the environmental. While there is no comprehensive source of information on the many individual PFAS substances and their functions in different applications, a range of resources are available to the practitioner. This guide provides information to assist the practitioner in navigating these challenges during the initial screening and site characterization process.

FIG. 1 Activity/Industry that may be Sources of PFAS Use and Release

Source: AEI Consultants

4.2 The user should note that PFAS regulatory management framework at the federal and state level are evolving quickly. Therefore, consultation with legal and technical representatives with knowledge of federal, state, and local PFAS regulations is advised prior to use of this guide. Environmental audit policies or privileges may be applicable to some of the steps described in this guide (see EPA, 2000).

4.3 Multi-step Risk Management Framework: 

4.3.1 The actions described in this guide are intended to provide a multi-step risk management framework to confirm, with reasonable certainty, that PFAS may have been used at a federally-owned, publicly-owned, or privately-owned property. This standard provides guidance on how to focus limited resources on using a multi-step process, illustrated in Fig. 2, to identify property potentially impacted by on-site or off-site uses and releases of PFAS. Section 4.5 describes the use and occurrence of PFAS. Section 4.6 describes activities at government and federal installations where PFAS use is expected. Section 4.7 broadly outlines the industry sectors where the use of PFAS has been documented (Glüge, 2020 (2), Gaines, 2022 (3)).

FIG. 2 Initial Site Screening and Characterization Flow Diagram

4.4 PFAs History and Use: 

4.4.1 In the 1940s, industrial processes to commercially produce PFAS were first developed. Since then, PFAS have been used to make many industrial and consumer products worldwide. Since the 1950s, PFAS have been widely used in surface treatment applications for paper, fabric, cookware and carpeting which allows these products and materials to repel oil, water, and stains. In the 1960s, the United States Navy used PFAS to develop Aqueous Film Forming Foam products for firefighting applications and the technology was patented by the U.S. Navy. Since the 1960s, the U.S. Food and Drug Administration (FDA) has authorized several broad classes of PFAS for use in food contact substances due to their non-stick and grease, oil, and water-resistant properties. Over the past 50 years, PFAS use has expanded in food and consumer products manufacturing and packaging and industrial operations and applications worldwide. Restrictions or prohibitions on the use of PFAS in food and consumer products have been enacted at the State and local level.

4.4.2 Release of PFAS during manufacture into the atmosphere may have occurred, and may be continuing to occur, followed by subsequent redeposition of PFAS materials on land where PFAS can enter surface water and groundwater. Other potential sources of PFAS emissions are dry cleaning and commercial laundry operations where clothing coated with PFAS-containing materials is cleaned or laundered. Emissions from these sources may include particulate matter such as lint. Additionally, PFAS may be or have been discharged without treatment to wastewater treatment plants or landfills, and eventually be released into the environment by treatment systems that are not designed to mitigate PFAS. Industrial discharges of PFAS were unregulated for many years; however, change is underway in the U.S. at both the state and federal level as well as internationally.

4.4.3 Broadly, consumer and industrial uses of PFAS-containing products and waste may release PFAS into landfills and landfill leachate, and into municipal wastewater, where it may accumulate undetected in biosolids which may be land applied. PFAS may be subsequently used in soil amendments used to grow animal feed and food crops and produce for human consumption. The user should be aware that federal, tribal, state, and municipal regulations affecting the management of PFAS, including air emissions, wastewater discharges, biosolids, groundwater, surface water, and impacted soil are rapidly evolving and may include additional reporting requirements. (4)

4.5 PFAs Use and Occurence: 

4.5.1 PFAS containing chemicals have been used in a broad spectrum of federal and commercial activities, as illustrated in Fig. 1. The use of PFAS as a component of AFFF for firefighting at military installations, refineries, petrochemical manufacturing facilities, tank farms, and airports is well known. PFAS are used as coatings for fabric and paper products to repel water and grease (see ITRC’s PFAS Technical Guide). PFAS have also been components of vapor control mists for electroplating operations. Other industrial uses of PFAS are described in this section as well.

4.6 Government and Military Installations Use of PFAs: 

4.6.1 PFAS have been used in a variety of applications at government/military facilities, including as a component in AFFF, which was routinely used at fire-fighting training areas and equipment test areas and is still used at crash sites and some fire suppression systems in hangars. In addition, PFAS has been a component of mist-suppression compounds associated with electroplating operations at federal facilities and government-owned, contractor-operated (GOCO) research and development plants. The wastewater treatment plants (WWTP) at federal installations may release PFAS as emissions and may discharge PFAS into receiving waters as effluent. The biosolids produced by the WWTP may contain PFAS if PFAS were present in the influent.

4.6.2 Current and historical AFFF storage and transfer areas at federally-owned facilities are of potential concern for release to the environment. Historical reports of uncontrolled spills and the repeated use of AFFF during fire training and firefighting have been correlated with higher concentrations of PFAS in surface water and groundwater. Discharges of liquids from fire-fighting practices into stormwater and sewer systems and holding ponds are potential source areas. In addition, treated effluents from remediation of other hazardous substances at the installation should be considered potential source areas.

4.6.2.1 Accordingly, key elements for identifying significant PFAS sources at federally-owned facilities are the storage and use of AFFF. PFAS from AFFF used in firefighting and fire suppression systems are considered to have the greatest potential for release of PFAS to the environment in terms of mass concentration at government/military installations.

4.6.2.2 Other potential sources of PFAS to the environment include historical on-site land disposal areas/landfills containing operations wastes (for example, from electroplating), wastewater treatment sludges and effluents, or PFAS materials themselves. Landfill leachate could carry PFAS to groundwater.

4.6.3 AFFF used in Fire-Fighting Exercises and Fire Suppression are water-based (60-90%) and frequently contain hydrocarbon-based surfactants, such as sodium alkyl sulfate, and fluorosurfactants, such as fluorotelomers, PFOA, and/or PFOS. AFFF containing PFAS were developed in the early to mid-1960s for use on Class B fires and were placed into routine use at government installations by the early1970s and are still in use today.

4.6.3.1 Companies including 3M, DuPont, Ansul, and Chemguard were the primary fire-fighting foam producers that used fluoro-chemical surfactants in the production of AFFF. Typically, AFFF concentrate was proportionally mixed into water lines using in-line eductors or other proportioning devices to create the necessary foam solution ranging from 3 % to 6 % of the concentrate. As noted, AFFF was primarily used with Class B fuel fires because the chemical properties of PFAS in AFFF created a thick foam blanket. Class A fire-fighting foams were used to extinguish wood and grass fires and do not contain PFAS.

4.6.4 Open Burning / Open Detonation of Munitions—Open burning and open detonation of munitions are non-routine activities at some military installations and federal facilities. The types of munitions that may contain PFAS are primarily limited to pyrotechnics (flares). The open- burning, open-detonation of munitions is subject to Subpart X of the RCRA Permitting Process (see 40 CFR 264, Subpart X).

Note 1: If the open detonation activities are conducted are part of the installation’s training program, they may not be subject to permitting under RCRA Subpart X. Temperatures in munitions deactivation furnaces and rotary kilns reach up to 1500°F, which may not be adequate to destroy PFAS (EPA, 2005). Open burning may not achieve temperatures high enough to destroy PFAS. The incomplete combustion of munitions as well as thermal deactivation releases PFAS into the air. Emissions associated with OB/OD of munitions travel downwind and should be considered in the fate and transport model. OB/OD may leave residual PFAS and metals in soil.

4.6.5 Electroplating, specifically hard chromium plating, is an industrial activity where PFAS-containing mist suppressants may have been used. PFAS were sometimes used during the chromium electroplating process as a surfactant in chromic acid baths. Federal facilities where electroplating may have been conducted include Department of Defense installations where aircraft, heavy equipment, and ships were overhauled and maintained. Government-owned, contractor-operated research and development plants are also sites where electroplating operations have historically been conducted.

4.6.6 Landfill Operations, Waste Disposal Areas, and Wastewater Treatment Plants—Historically, landfills received wastes generated from government/military installations, including waste streams from operational areas (machine shops, electroplating operations, etc.), housing areas, and waste from wastewater treatment plants. These waste streams may contain industrial and/or consumer products that were either manufactured with PFAS or contain compounds that, when they degrade, release PFAS, which may leach out of the landfill. Additionally, waste material biosolids and sludge from WWTPs can contain PFAS.

4.7 Commercial and Industrial Uses of PFAs: 

4.7.1 Uses of PFAS in commercial applications are varied and span numerous commercial and industrial sectors (Gaines 2022) (3). This guide is focused on potential sources of significant releases of PFAS to the environment. Some examples of industries where PFAS have been used in production and manufacturing include:

4.7.1.1 Chemical industry with a special focus on processing aids in the polymerization of fluoropolymers,

4.7.1.2 Surface protection of textile, apparel, leather, carpets, and paper,

4.7.1.3 Electronics industry (semiconductors and wire; NAICS 334400 and 335929, respectively) (Note: and solar panels),

4.7.1.4 Consumer and personal care products,

4.7.1.5 Food processing and packaging,

4.7.1.6 Plastics and rubber production,

4.7.1.7 Pulp and paper industry,

4.7.1.8 Coatings, paints, and varnishes,

4.7.1.9 Refinery and petrochemical industry,

4.7.1.10 Munitions and explosives production,

4.7.1.11 Aircraft and heavy equipment manufacturing,

4.7.1.12 Public-sector and private-sector airports, and

4.7.1.13 Electroplating of parts and components.

4.7.2 As noted in section 4.6.5, electroplating, specifically hard chromium plating, is an industrial activity where PFAS-containing mist suppressants may have been used. PFAS were sometimes used during the chromium electroplating process as a surfactant in chromic acid baths.

4.7.3 Chemical industry with a special focus on processing aids in the polymerization of fluoropolymers. Important uses of PFAS in the chemical industry are their uses as processing aids in the polymerization of fluoropolymers, the production of chlorine and sodium hydroxide, and the production of other chemicals including solvents. PFAS that are used as processing aids in the polymerization of fluoropolymers are of special concern due to emissions and toxicity (Lohmann, 2020) (5).

4.7.4 Surface Protection of Textile, Apparel, Leather, Carpets, and Paper—Considerable quantities of PFAS, especially of side-chain fluorinated polymers, have been used as surface protectors in textile, apparel, leather, carpets, and paper. Paper products that may contain PFAS include food wrapping, pizza boxes, microwave popcorn. These are open and dispersive uses where many consumers come into contact with the PFAS-containing products. The side-chain fluorinated polymers contain perfluoroalkyl acids as impurities and they may act as important precursors to PFAS. Many PFAS precursors (such as alcohols, amides) can be degraded to perfluoroalkyl acids (OECD, 2007; Buck, R.C. et al. 2011 (6)).

Note 2: Toxicological and ecotoxicity assessments of perfluoroalkyl acids are in their nascent stage.

4.7.5 Electronics Industry—PFAS have been used as components in electronic devices (for example, in flat panel displays or liquid crystal displays). PFAS have also been used for the testing of electronic devices and equipment, as heat transfer fluids/cooling agents, in cleaning solutions, to deposit lubricants, and to etch piezoelectric ceramic filters. PFAS are also used in the production of semiconductors and wiring.

4.7.6 Plastics and Rubber Production—PFAS have been used as mold release agents, foam blowing agents, foam regulators, polymer processing aids, plastic etching agents, anti-blocking agents for rubber, and curatives in the production of plastic and rubber. Fluoropolymers can increase the processing efficiency and quality of plastic and rubber. The use of PFAS in the production of plastic and rubber may explain why PFAS are found in final products, for example, in artificial turf.

4.7.7 Coatings, Paints, and Varnishes—Large amounts of fluoropolymers have been used in coatings and paints to impart oil- and water-repellency. Fluoropolymers are also used as anti-stick and anticorrosive coatings.

4.7.8 Refineries and Petrochemical Industries—As noted previously, AFFF containing PFAS has been used for fire suppression at petroleum refineries, petrochemical manufacturing operations, and bulk storage and distribution terminals. The fire suppression systems at these facilities are subject to period testing. Fire suppression water containing AFFF may collect in holding ponds prior to being processed in the plant’s WWTP or discharged.

4.7.9 Munitions and Explosives Production—PFAS is used in a small percentage of energetics as binders and oxidizers, and in some military munitions for liners, o-rings, or other components (SERDP 2020) (7). Manufacturers of munitions have historically released PFAS through open-burning of munition waste.

4.7.10 Aircraft and Heavy Equipment Manufacturing—Industries that use electroplating in the production and manufacturing of parts and equipment may have used PFAS-containing chemicals.

4.7.11 Public-Sector and Private-Sector Airports—AFFF containing PFAS has been used for fire suppression training at certain airports, including the bulk fuel storage tanks. The fire suppression training using AFFF is conducted periodically at airports. Fire suppression water containing AFFF may collect in holding ponds prior to being processed in the airport’s on-site WWTP, discharged to stormwater conveyance systems, or flow to an off-site WWTP.

4.7.12 Carwashes—PFAS are a component of the soap and waxes at commercial car washes (NAICS code 811192). Sumps and catch basins at a carwash that have lost their structural integrity may be a source of releases.

Subcomité:

E50.04

Volúmen:

11.05

Número ICS:

71.040.50 (Physicochemical methods of analysis)

Palabras clave:

AFFF; conceptual site model; corrective action; exposure pathways; initial site characterization; munitions; PFAS; risk assessment; site-screening; stack emissions;