Related EPA Actions
- Inerts in Pesticides, including PFOA-related Chemicals
- PFOA-related Research
- National Exposure Research Laboratory (NERL)
- National Health and Environmental Effects Research Laboratory (NHEERL)
- National Risk Management Research Laboratory (NRMRL)
- Monitoring PFOA in Water
- Provisional Health Advisories for PFOA and PFOS
- Science Seminar
- Science Presentations
Pesticide products contain both "active" and "inert" ingredients. The terms "active ingredient" and "inert ingredient" have been defined by Federal law under the 1947 Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). An active ingredient is one that prevents, destroys, repels or mitigates a pest, or is a plant regulator, defoliant, desiccant or nitrogen stabilizer. By law, the active ingredient must be identified by name on the label together with its percentage by weight.
An inert ingredient means any substance other than an active ingredient, which is intentionally included in a pesticide product. Inert ingredients play a key role in the effectiveness of a pesticidal product. For example, inert ingredients may serve as a solvent, allowing the pesticide's active ingredient to penetrate a plant's outer surface. In some instances, inert ingredients are added to extend the pesticide product's shelf-life or to protect the pesticide from degradation due to exposure to sunlight. Pesticide products can contain more than one inert ingredient, but federal law does not require that these ingredients be identified by name or percentage on the label. Only the total percentage of inert ingredients is required to be on the pesticide product label. Read more information on inert and active ingredients in pesticides.
In 2006, the EPA revoked safe tolerance levels for as many as 130 inert pesticide ingredients currently exempted from tolerance levels, including PFOA related chemicals, because there was insufficient data available to make a safety determination. Read more information on "Inert Ingredient; Revocation of the Tolerance Exemption for Mono- and Bis-(1H,1H,2H,2H-perfluoroalkyl) Phosphate Where the Alkyl Group is Even Numbered and in the C6-C12 Range."
PFOA related Research
EPA's Office of Research and Development (ORD) has PFC research underway at multiple EPA labs. ORD research supports OPPT's needs identified in the PFOA ECA process to understand PFC sources and pathways. EPA ORD is conducting research in several areas, including:
- Telomer biodegradation research
- Methods development for environmental, biota, and biological matrices
- Aged article research
- Toxicology and pharmacokinetics
- PFC distribution in environmental matrices
In the summer of 2006, a “PFAA Days (PDF)" workshop (60pp., 871.66kb About PDF) was held at the US EPA ORD’s facility in Research Triangle Park, NC where scientists and managers from the Office of Prevention, Pesticides, and Toxic Substances (OPPTS), the Office of Water (OW), the EPA Regions, and various offices and laboratories within ORD assembled to learn of the research plans and activities of investigators in NHEERL, NERL and NRMRL, to exchange perspectives, and to identify research needs for risk assessment. The workshop was highly successful, in that valuable insights were gained by all participants.National Exposure Research Laboratory (NERL)
NERL is conducting research on biodegradation of fluorotelomers and fluorotelomer-based polymers, which is a scientific issue related to how PFOA and related compounds can enter the environment. The decision to test the biodegration of fluorotelomers and fluorotelomer-based polymers emerged from the ECA Process. The laboratory derives detection-limit definitions suitable for determining the presence or absence of PFCAs and FTOHs in soils. NERL has developed extraction techniques and analysis methods that allow for the detection of low levels of PFCAs and FTOHs in soils, sediments, fluorotelomer-based polymers and sewage sludge. The development of a sequential extraction method for soil-polymer microcosms have allowed high recoveries of FTOHs, acrylates, PFCAs and other perfluorinated compounds, all from single microcosms. In recent development, the last round of 550-day incubation with a purified polymer was completed -- and these data were subjected to statistical analysis, with the subsequent development of a conceptual-model, a quantitative initial model, and steady-state degradation-rate model. In addition, a refined extraction methodology was developed for FTOHs, fluorotelomer acrylates, and fluorotelomer olefins in soils. A more exhaustive sludge-extraction was developed for the cleanup and analysis methods allowing for the detection of low PFCAs and other PFCs.
NERL has also developed methods for extraction, cleanup, and analysis of PFOA in blood serum and tissue homogenates. It has developed methods for the analysis of PFAAs in surface water, and similar efforts are underway to develop methods of extraction of PFAAs for soil, fish tissue, food, and breast milk. In addition, the detection of soil contamination from application methods such as spray field irrigation, sewage sludge application, and areas in close proximity to manufacturing is currently under development. Read more information on PFCs from the National Exposure Research Laboratory (NERL).
National Health and Environmental Effects Research Laboratory (NHEERL)
NHEERL research on PFAAs focuses on three areas: (1) understanding of the pharmacokinetic properties of these chemicals; (2) characterization of the toxicological features that are common to this class of compounds; and (3) investigation of their modes of action to improve the extrapolation of findings from animal studies to human health risk assessment. NHEERL conducted pharmacokinetic studies with perfluoroalkyl carboxylates (PFOA, PFBA) in the rodent models, the results were applied to computational analyses to describe the profiles of tissue distribution and accumulation, to discern the potential differences between genders and among ages, and to simulate chronic exposure to low doses of these chemicals (human scenarios). Characterization of potential adverse health effects includes evaluation of developmental toxicity, hepatotoxicity, immunotoxicity, and endocrine disruption in rodent models after subchronic exposure to PFOS and PFOA. The modes of action for PFAA toxicity are being investigated by a number of biochemical and physiological studies, employing in vivo and in vitro (transfected cell culture) models, toxicogenomic approaches and various transgenic mouse models.
Results generated from NHEERL's research will reduce uncertainty in risk assessment by:
- characterizing the developmental toxicity of PFOS, which may provide the most sensitive index for risk assessment
- characterizing the PK parameters of PFOA in a mouse model that resembles more closely to the human PK profile
- identifying the mouse as a suitable model for PFOA developmental toxicity study
- constructing computational PK models to facilitate animal-to-human extrapolation
- elucidating different modes of action for PFOS- and PFOA-induced developmental toxicity
- using toxicogenomic approaches to elucidate the mechanisms of PFAA-induced hepatotoxicity
- demonstrating that PFOS crosses the blood-brain barrier in the immature rat brain, prompting industry to initiate additional developmental neurotoxicity studies
- identifying thyroid hormone disruption as a common feature for most PFAAs
- contributing to peer-reviewed toxicity literature thereby allowing the experimental data to be used for benchmark modeling by regulatory agencies
- organizing national and international workshops to engage research and regulatory partners and provide leadership in this field
- providing prompt responses to state health department inquiries
National Risk Management Research Laboratory (NRMRL)
NRMRL's research is focused in two areas: fate of FCs in wastewater systems, and aged article emissions.
Wastewater research has involved developing analytical chemistry methods and evaluating fate through the activated sludge process. The decision to conduct research on wastewater systems emerged from the ECA Process. Analytical chemistry for wastewater is difficult due to the complex matrix and due to complications in quantitation due to signal enhancement and suppression by interfering compounds. Therefore, NRMRL is developing methods to extract and clean up samples from wastewater matrices. Quantitation will use a GC-MS method for telomer alcohols and an LC-MS method for acids. Research on activated sludge processes relies on modified-OECD semi-continuous activated sludge (SCAS) testing protocols. Modifications have included: evaluating sludge feed sources for routine operations; and adapting reactor configurations and reactor volumes to optimize routine sampling and operations. This research will provide OPPT with environmental data characterizing some of the sources associated with elevated levels of fluorinated carboxylic acids observed in human health and wildlife surveys.
The data generated from NRMRL's research will provide data on the fate of "down the drain" disposal of consumer products. Furthermore, it will also provide data on reaction pathways for fluorotelomer-based polymers (FBPs) and the release of PFOA into the environment. In the future, wastewater research will be expanded to include anaerobic biological treatment processes and biosolids disposal, such as sludge digesters and land treatment, and the characterization of wastewater effluents for PFCAs, FTOHs, and associated compounds.
NRMRL is also involved in the testing of aged articles of commerce (AAOC). The decision to test emerged from the AAOC ECA Process. Research at NRMRL is focused on whether telomer and fluoropolymer treated articles could release PFOA as they age, contributing to exposures. The aged article testing will determine the content of PFOA and its homologues, C5 to C12, in new consumer products, and evaluate PFOA's releases from consumer products by accelerated aging tests and tests under close-to-realistic exposure conditions, and evaluate risk management options for reducing PFOA exposure in homes and offices. Read more information on ORD's AAOC testing (PDF) (50pp, 1.3MB, About PDF) and a study on perfluorocarboxylic acid content in 116 articles of commerce.
Monitoring PFOA in Water
The EPA's Office of Ground Water and Drinking Water (OGWDW) within the EPA's Office of Water (OW) regulates contaminates in the nation's ground water and drinking water systems. The EPA has drinking water regulations for more than 90 contaminants. The Safe Drinking Water Act (SDWA) includes a process that identifies and lists unregulated contaminants which may require a national drinking water regulation in the future. EPA periodically publishes this list of contaminants, which is called the Contaminant Candidate List (CCL), and decides whether or not to regulate at least five or more contaminants from the list. EPA also uses this list of unregulated contaminants to prioritize research and data collection efforts to help determine whether or not specific contaminants should be regulated in drinking water. Read further information on the Contaminant Candidate List.
In 2009, the CCL 3 included 104 chemical contaminants or groups and 12 microbes. Among them are contaminants, pesticides, disinfection byproducts, pharmaceuticals, chemicals used in commerce, waterborne pathogens and algal toxins. The agency’s selection of the contaminants builds upon evaluations used for previous lists and is based on substantial expert input and recommendations from different groups including stakeholders, the National Research Council and the National Drinking Water Advisory Council. EPA will make regulatory determinations for at least five contaminants in accordance with the Safe Drinking Water Act. For those CCL 3 contaminants that lack sufficient information for a regulatory determination by 2013, EPA will encourage research to provide the information needed.
As part of the Safe Drinking Water Act (SDWA), EPA is required to establish criteria for a program to monitor unregulated contaminants and identify no more than 30 contaminants to be monitored every five years. EPA identified and published unregulated contaminants for the first direct-implementation of UCMR (i.e., UCMR 1) and a revised approach for monitoring in the Federal Register dated September 1999. UCMR 1 established a tiered monitoring approach, and required all public water systems (PWSs) serving more than 10,000 people and a representative sample of PWSs serving 10,000 or fewer people to monitor for unregulated contaminants from 2001-2005. The second rule, UCMR 2, required PWSs to monitor during a 12-month period from 2008-2010. In 2011, as proposed, UCMR 3 would require public water systems (PWSs) to monitor for 28 chemicals, including six perfluorinated chemicals, and two viruses. All PWSs serving more than 10,000 people, and a representative sample of 800 PWSs serving 10,000 or fewer people, would be required to conduct Assessment Monitoring for 28 "List 1" chemicals during a continuous 12-month period from January 2013 through December 2015. Read further information on the Unregulated Contaminant Monitoring Rule (UCMR) 3.
In November 2010, EPA published the second list of chemicals for Tier 1 Screening for the Endocrine Disruptor Screening Program (EDSP). This list of 134 chemicals includes a large number of pesticides, two perfluorocarbon compounds (PFCs), and three pharmaceuticals (erythromycin, nitroglycerin, and quinoline). Read further information on the EDSP.
Provisional Health Advisories for PFOA and PFOS
On January 9, 2009, EPA's Office of Water (OW) developed Provisional Health Advisories for PFOA and PFOS to protect against potential risk from exposure to these chemicals through drinking water. Provisional Health Advisories serve as informal technical guidance to assist Federal, State and local officials in response to an urgent or rapidly developing drinking water contamination. They reflect reasonable, health-based hazard concentrations above which action should be taken to reduce exposure to these contaminants in drinking water. The PHA values are 0.4 µg/L for PFOA and 0.2 µg/L for PFOS. Theses values may be used to assess contamination and exposure at other sites. Provisional Health Advisories are not to be construed as legally enforceable federal standards and are subject to change as new information becomes available. Read further information on PFOA and PFOS Provisional Health Advisories here.
DuPont and 3M/Dyneon collaborated to offer a science presentation on the findings from their research programs on perfluorinated chemicals for OW on October 15 and 16, 2009. Representative scientists from both industries presented data on the toxicology, toxicokinetics, and environmental fate of representative compounds from the perfluorinated acid and sulfonate families concentrating primarily on PFOA and PFOS. Both chemicals are included on the OW Contaminant Candidate List 3 and of interest because of their presence in drinking water, surface waters, private wells, and biosolids. Information on analytical methods and treatment technologies supplemented the toxicology discussions. EPA scientist from OW, OPPT, ORD and several EPA Regions took part in this seminar either in person or through teleconferencing arrangement. In addition to the DuPont and 3M/Dyneon scientists and allied researchers, representatives from Asahi Glass, Daikin, and Clariant were also in attendance. Read further information on the meeting agenda (3 pp, 61 KB). The presentations below are available at EPA-HQ-OPPT-2003-0012.
|Introduction and Overview (PDF)(12pp, 126kb)||Etiology of Biological Responses and Human Relevance (PDF) (55pp, 3.25MB)|
|Human Biomonitoring and Epidemiology (PDF) (146 pp, 1.85MB)||Risk Assessment Approaches (PDF) (28pp, 437KB)|
|Pharmacokinetic and Mechanistic Issues (PDF) (43pp, 553KB)||Analytical Issues (PDF) (34pp, 552KB)
|Pharmacokinetic Modeling (PDF) (35pp, 1.99MB)||Physical Chemical Properties/Environmental Fate (PDF) (41pp, 1,59MB)|
|Toxicology - Sulfonates (PDF) (37pp, 149KB)||Water Treatment Methodologies (PDF) (26pp,1.02MB)|
|Toxicology - Carboxylates (PDF) (48pp, 369KB)|