Working safely with PFAS containing aqueous film-forming firefighting foams - Technical guide

This document is to provide technical information to current and ex-workers in addressing the potential health concerns on the use, handling and storage of PFAS containing aqueous film forming foams (AFFF) and their contaminants.

AFFF

Aqueous film forming foams (AFFF) are water-based fire-fighting foam products used to suppress flammable liquid fires. They contain a class of stable chemical substances called per- and poly-fluoroalkyl substances (PFAS). This class of chemical substances include perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).

Some PFAS are extremely persistent in the environment and are resistant to typical environmental degradation. They have been found in surface water, ground water, soil, and sediment, especially near facilities that have made or used these substances. Some Long-chain PFAS also remain in the body unchanged for long periods of time and may increase their concentration in the tissues of organisms as it travels up the food chain. PFAS have been detected in blood, and at much lower levels in urine, breast milk and in umbilical cord blood in exposed populations. They also persist in the human body and are eliminated slowly. It takes approximately 2-4 years for the level of PFOA and 5-6 years for the level of PFOS to reduce by half in a human body. PFAS leave the body primarily through urine (1).

Human health and PFAS

The US National Centre for Environmental Health of the Centres for Disease Control and Prevention (CDC) published information on a large epidemiology study (the C8 Health Project) that included workers exposed to PFAS and people living near a PFOA facility (2). This project found links between elevated PFOA blood tests and high cholesterol, ulcerative colitis, thyroid function, testicular cancer, kidney cancer, preeclampsia, as well as elevated blood pressure during pregnancy.  The study showed PFAS exposure was linked to several health issues.  However, because the observed health effects can be caused by many other factors that could not be controlled for, or unrelated to their exposure to PFOA, no conclusive linkage can be established between PFAS exposure and future health problems in humans.

The mode of action for some PFAS to cause adverse health effects on animals (mouse) and humans, is believed to be through activation of Peroxisome Proliferator-Activated Receptor Alpha (PPARα) (2, 3). The regulation of these receptors, however, was shown to differ among species (4, 5, 6). In vitro studies have further suggested that the mouse PPARα to be more sensitive to PFAS than the human PPARα (3). Data to assess the acute toxicity of PFAS following high exposure in humans is inadequate. Animal data suggests PFAS to have moderate acute toxicity and a range of adverse health effects following chronic exposure. These include effects on the liver, gastrointestinal tract, altered lipid metabolism, thyroid hormone levels and increased risk of spontaneous abortion (1). However, currently no conclusive decision can be made from animal data.

Similarly, there is some evidence that PFOS and PFOA could cause cancer in humans and in experimental animals. However, none of the evidence is convincing enough to establish a causal link between PFOS and PFOA and cancer in humans. In Australia, PFOS and PFOA are classified as chemicals that are suspected of causing cancer (GHS carcinogenic category 2) (7).

It is important for the scientific community to use these associations to inform future research. However, at this stage no clear causal relationship has been found between PFAS and any specific health outcome (9, 10).  The likelihood of adverse effects also depends on several factors, such as the amount and type of PFAS that people are exposed to, as well as the frequency and time span of exposure (1, 8).  All these factors must be carefully considered in the interpretation of epidemiology and animal research data.

Other sources of PFAS

Apart from their use as firefighting foams, PFAS have been widely used in homes and offices including in stain repellent fabric and carpet coatings. Until recently, consumables could be packaged in materials containing PFAS (e.g., popcorn bags, fast food containers, and pizza boxes). Because of past exposure, most Australian have detectable levels of PFOA and PFOS in their blood.  This is evident in the biomonitoring data collected in Australian between 2011-2012 (11, 12).

Restricted use of PFAS containing AFFF in Australian fire services

Since 2003, the Australian National Industrial Chemicals Notification and Assessment Scheme (NICNAS) recommended restricting PFOS containing AFFF to essential use only. State and territory agencies have been working with industry on voluntary changes. In 2007, PFOS and PFOA containing AFFF were withdrawn from service (including use on fires and training sites) within Fire & Rescue NSW.

Because of the good fuel shedding and suppression properties of AFFF, some fire services in NSW and Major Hazard Facilities (MHF) such as petrochemical facilities and dangerous goods storage facilities, still hold stocks of PFAS containing AFFF for emergency use. The Queensland and South Australia State Government are banning the future use of PFOS and PFOA containing AFFF for firefighting and a national phase out of PFOS is under consideration by the Australian Government following the ratification of the Stockholm Convention amendment on PFOS (13, 14, 15).

There are some non-PFOS products available on the market and some users of PFOS-containing firefighting foams have already transitioned to these products. Some of these alternative products use other PFAS as a surfactant, while others are fluorocarbon or fluorine free. (16, 17).  Their effect on environment and human health is uncertain and they should be used with caution.

Affected workers in NSW

Workers most likely to have concerns regarding PFAS containing AFFF exposure include:

  1. Workers, including fire fighters who may have been exposed to PFAS containing AFFF;
  2. Fire fighters, including volunteer and workers, when existing PFAS containing AFFF stock are used for emergency fire suppression;
  3. Workers exposed to existing PFAS containing AFFF stock when managing waste and accidental spills;
  4. Workers undertaking remediation tasks in PFAS contaminated sites, such as, the Royal Australian Air Force (RAAF) base at Williamtown, NSW;
  5. People who work in or near PFAS Investigation/Management areas.

Note: NSW Environment Protection Authority (EPA) is working with other NSW Government agencies under the PFAS investigation program to identify sites that may have high PFAS level and may require remediation (18).

Workers exposed to PFAS contained in AFFF

The primary exposure pathways in the workplace are inhalation of spray mist and dust contaminated with PFAS. Skin contact is a minor exposure pathway, as skin absorption of liquid PFAS is slow and unlikely to result in significant absorption (1). Unlike general population where dietary ingestion is the dominant source of PFAS exposure, at work, exposure through ingestion is not common.  Nevertheless, overseas studies have showed people who work where perfluoroalkyls are manufactured or used in their raw form were also found to have higher levels of PFOS and PFOA in their blood than levels in people from the same communities who did not work at these locations (19). These workers may have been accidentally exposed through ingestion of PFAS contaminated-water/dust or home grown produce in those areas.

Workers can also be exposed to PFAS outside their workplace. Exposure can occur through exposure to PFAS from the air, indoor dust, food, drinking PFAS contaminated water and from various consumer products, such as stain repellent fabric, carpet coatings, popcorn bags and fast food containers.

How workers can reduce the risk of exposure to PFAS contained in AFFF

The risk of exposure to PFAS must be minimised in the workplace wherever possible. Where elimination is not possible, the risk of exposure must be assessed and managed in accordance with the hierarchy of exposure controls and have regard for safe work procedures and recommendations given in the Safety Data Sheets (SDS). Personal Protective Equipment (PPE) is a low level of control and should not be applied as a primary control without due consideration of other options (20).

In firefighting situations

Fire fighters may be exposed to PFAS containing AFFF as well as other hazardous chemicals in firefighting situations.  Full structural firefighting uniform, including gloves and respiratory protection, must therefore be worn at all times as recommended by Fire and Rescue NSW (21). More information is available from Fire & Rescue NSW PFAS Questions and answers.

In spills, decontamination and disposal situations

For fire fighters decanting or pouring PFAS containing AFFF, or workers decontaminating firefighting equipment and accidental spills of AFFF, a minimum level of personal protective clothing and equipment (PPE) including: rubber gloves, P2 respirators, duty wear/overalls and splash proof goggles must be worn at all times as recommended by Fire and Rescue NSW (21).

Workers undertaking remediation tasks in PFAS contaminated sites

It is understood that workers in PFAS contaminated sites may encounter in addition to PFAS, other known and unknown hazards at any stage. It is therefore important to conduct and review control measures through all stages of assessment, remediation and management (22). Workers may need to use a range of PPE according to the type and level of contamination. This include boots, respirators, gloves, and chemical protective clothing. The highest order of control should always be employed.

(Note: Other contaminants may include substances such as volatile organic solvents, fuels such as petrol and diesel, heavy metals, pesticides and various hazardous wastes. They may be found in the soil or groundwater and can present a health risk to workers.)

Workers who are undertaking remediation tasks in PFAS contaminated sites are also advised not to use groundwater, bore water, surface water or home grown produce for any purpose as advised by the NSW Health and NSW EPA to residents in contaminated areas (23, 24).

More information on the management of PFAS found in contaminated sites is available on the Department of Environment Regulation, Western Australia website (25).

People who work in or near PFAS Investigation/Management areas

People who work in or near PFAS Investigation/Management areas should follow the same precautionary measures in the use groundwater, bore water, surface water or home grown produce as advised by the NSW EPA for residents. This advice is site specific, for example, the NSW EPA has recommended a set of precautionary advice for residents in the entire (primary, secondary and broader) management area at the Williamtown Air Force base (24).

What to do if workers are concerned about PFAS exposure

There is no consistent evidence that PFAS cause specific illnesses in humans, including cancer. Additional health studies are ongoing to assess whether evidence for a causal link between PFAS exposure and cancer may exist (9).  However, if you are concerned about previous exposure or if you believe you have been exposed to high levels of PFAS at work, you should seek advice from an occupational physician as a precautionary measure.  More information can be found at The Australasian Faculty of Occupational and Environmental Medicine (AFOEM). The Federal Department of Health has currently also put in place a voluntary blood testing program for people who have lived or worked around RAAF Base Williamtown, NSW where elevated levels of PFAS have been detected (10).

There is a test by specialist laboratories to measure the amount of PFAS in blood (12).  However, as PFAS tends to remain in the body unchanged for long periods of time, it is common for general public to have trace background levels of PFAS in their blood because of past exposure from other sources of PFAS (11).

The presence of PFAS in blood serum does not necessarily mean that there will be adverse health effects and it cannot be conclusively determined if this exposure is from work. At present, blood testing does not add further value in informing clinical management, including diagnosis, treatment or prognosis in terms of increased risk of any particular condition over time (4). Hence, blood tests are not recommended to determine whether any medical condition is attributable to exposure to PFAS exposure.

Australian workplace exposure limit for PFAS

There is no Australian Workplace Exposure Standard (WES) for airborne and biological occupational exposure level for blood concentration of PFOS and PFOA. Although health based guidance values on tolerable daily intake for PFAS are available, these values indicate the amount of PFAS in food or drinking water that a person can consume on a regular basis over a lifetime without any significant risk to health (26). They do not indicate occupational exposure limits.

SafeWork NSW’s position on management of PFAS containing AFFF at the workplace

PFAS containing AFFF should be risk managed in the same manner as other known hazardous workplace chemicals under the WHS Regulation (19).

Health monitoring for PFAS is currently not recommended for workers as the presence of PFAS in blood does not necessarily mean that there will be adverse health effects. Currently it does not add any further value in informing clinical management.

Most people have background levels of PFOA and PFOS in their body due to lifestyle exposure. PFAS take a very long time to reduce in humans. Therefore, current levels in the blood may reflect exposure from years ago and not necessarily recent exposure.  Unless there is significant exposure, it would be difficult to identify the source of contamination.  An analytical level, be it high or low, can lead to unnecessary anxiety and adds no significant health benefit.

However, if you are concerned about previous exposure or if you believe you have been exposed to high levels of PFAS at work, as a precautionary measure, you should seek expert advice from an occupational physician.

References

  1. An overview of Perfluoroalkyl and Polyfluoroalkyl substances and Interim Guidance for Clinicians responding to patient exposure concerns (2017) Agency for Toxic Substances and Disease Registry, National Center for Environmental Health, US. Available on line: https://www.atsdr.cdc.gov/pfc/docs/pfas_clinician_fact_sheet_508.pdf(Accessed on 18 December 2017)
  2. Wolf CJ, Schmid JE, Lau C et al (2011) Activation of mouse and human peroxisome proliferator-activated receptor-alpha (PPARα) by perfluoroalkyl acids (PFAAs): Further investigation of C4-C12 compounds. Reproductive Toxicology 33(4):546-51
  3. Wolf CJ, Takacs ML, Schmid JE et al (2008) Activation of Mouse and Human Peroxisome Proliferator-Activated Receptor Alpha by Perfluoroalkyl Acids of Different Functional Groups and Chain Lengths. Toxicological Sciences 106(1):162-71
  4. Albrecht PP, Torsell NE, Prasad Krishnan et al (2013)A Species Difference in the Peroxisome Proliferator-Activated Receptor α-Dependent Response to the Developmental Effects of Perfluorooctanoic Acid. Toxicological Sciences, 131(2), 568–582
  5. Lawrence JW, Li Y and Chen SY et al (2001) Differential gene regulation in human versus rodent hepatocytes by peroxisome proliferator-activated receptor (PPAR) α - PPARα fails to induce peroxisome proliferation-associated genes in human cells independently of the level of receptor expression.  Journal of biological chemistry 276, 3151-3152
  6. Mukherjee R, Jow L, Noonan D, McDonnell DP (1994) Human and rat peroxisome proliferator activated receptors (PPARs) demonstrate similar tissue distribution but different responsiveness to PPAR activators. J Steroid Biochem Mol Biol. 51(3-4):157-66
  7. Hazardous Chemical Information System, Safe Work Australia, Available on line: http://hcis.safeworkaustralia.gov.au/ (Accessed on 13 March 2018)
  8. Public Health Statement-Perfluoroalkyls (2015) Agency for Toxic Substances and Disease Registry, Department of Health and Human Services, Public Health Services, US
  9. PFOS and PFOA Factsheet (2017) NSW Health, NSW Government.  Available on line: http://www.health.nsw.gov.au/environment/factsheets/Pages/pfos.aspx (Accessed on 18 December 2017)
  10. Per- and Poly-fluoroalkyl substances (PFAS) (2017) Department of Health, Australian Government. Available on line: http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-pfas.htm#pfas (Accessed on 18 December 2017)
  11. Aylward LL, Green E, Porta M et al., (2014) Population variation in biomonitoring data for persistent organic pollutants (POPs): An examination of multiple population-based datasets for application to Australian pooled biomonitoring data. Environ Int.; 68:127-38
  12. Voluntary Blood Testing Program for PFAS-Post-test consultation advice for GPS, Department of Health, Australian Government. Available on line: http://www.hneccphn.com.au/media/13896/j2906-factsheets_pfas-post-test-consultation-advice-for-gps_v1-d16-13.pdf. (Accessed on 16 March 2018)
  13. National phase out of PFOS. Ratification of the Stockholm Convention amendment on PFOS (2017) Department of the Environment and Energy, Australian Government
  14. PFAS firefighting foam ban and phase out (2017) Queensland Government.  Available on line: https://www.qld.gov.au/environment/pollution/management/investigation-pfas/firefighting-foam (Accessed on 18 December 2017)
  15. SA Bans fluorinated firefighting foams (2018) Fire Protection Association Australia.  Available on line: http://www.fpaa.com.au/news/news/sa-bans-fluorinated-firefighting-foams.aspx (assessed on 13 March 2018)
  16. Operational Policy. Environmental Management of firefighting foam (2016) Department of Environment and Heritage Protection, Queensland Government
  17. Environmental management of firefighting foam policy: Explanatory notes revision 2 (2016) Department of Environment and Heritage Protection, Queensland Government
  18. PFAS investigation program FAQs (2017) NSW EPA. Available on line: http://www.epa.nsw.gov.au/working-together/community-engagement/pfas-investigation-program/pfas-investigation-faqs(Accessed on 18 December 2017)
  19. Aqueous Film Forming Foams (AFFF)/PFAS Information Sheet (2017) Department of Defence, Defence People Group, Australian Government
  20. Code of Practice for managing risks of hazardous chemicals in the workplace (2012) Safe Work Australia
  21. Uniforms and equipment (2017) Fire & Rescue NSW, NSW Government. Available on line: https://www.fire.nsw.gov.au/page.php?id=164. (assessed on 3 April 2018)
  22. Guidance note: Occupational Safety and Health Management and contaminated sited work. Guidance for employers, employees, site owners, consultants, self-employed people and contractors (2005) Commission for occupational safety and health. Government of Western Australia
  23. Williamtown RAAF Base contamination (2017) NSW EPA. Available on line: http://www.epa.nsw.gov.au/working-together/community-engagement/community-news/raaf-williamtown-contamination (Accessed on 9 January 2018)
  24. Ground water (2018) NSW Health. Available on line: http://www.health.nsw.gov.au/environment/water/Documents/groundwater-treatment-fact-sheet.pdf. (accessed on 29 Jan 2018)
  25. Interim Guideline on the assessment and management of perfluoroalkyl and polyfluoroalkyl substances (PFAS) Contaminated sites Guidelines (2016) Department of Environment Regulation, Western Australia website, available on line: https://www.der.wa.gov.au/images/documents/your-environment/contaminated-sites/guidelines/Guideline-on-Assessment-and-Management-of-PFAS-.pdf. (Accessed 10 March 2018)
  26. Health based guidance values for PFAS for use in site investigations in Australia (2017) Department of Health, Australian Government. Available on line: https://www.health.gov.au/internet/main/publishing.nsf/Content/2200FE086D480353CA2580C900817CDC/$File/fs-Health-Based-Guidance-Values.pdf. (Accessed on 12 March 2018)

Prepared by: Hygiene and Toxicology Team - SafeWork NSW - April 2018

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