Flame retardant chemicals have been added to polyurethane foam, textiles, building materials, electronics and other consumer products to meet flammability standards, including California's Technical Bulletin 117 (TB 117). Flame retardants may be mixed with the base material (additive flame retardants) or may be chemically bonded to it (reactive flame retardants). Additive flame retardants can escape from consumer products and settle into house dust. Contact with dust is the major route of exposure to flame retardants, particularly for children. Due to the widespread use, Americans carry much higher levels of flame retardants in their bodies than anyone else in the world, and California children have some of the highest levels ever reported.
Not all flame retardants are toxic, but members of the following classes often are:
Halogenated flame retardants persist in the environment and build up in freshwater, marine, and terrestrial ecosystems globally, with the highest levels in predators such as marine mammals and birds of prey. Exposures to some halogenated flame retardants have been linked to adverse health effects in animals and humans, including endocrine and thyroid disruption, immunotoxicity, reproductive toxicity, cancer, and adverse effects on fetal and child development and neurologic function. Some organophosphate flame retardants are human carcinogens.
TB 117 was revised because it did not adequately address the flammability performance of upholstery cover fabric and its interactions with underlying filling materials. The new standard, TB 117-2013, effective January 1, 2015, is intended to improve fire safety and often eliminates the need for flame retardant chemicals. It does not preclude their use, however.
ARE LEVELS OF PBDEs DROPPING?
Two recent studies by DTSC scientists showed that PBDE levels were decreasing.
The first study (Guo W, Holden A, Crispo-Smith S, Gephart R, Petreas M, Park J-S. (2015): PBDE Levels in Breast Milk Are Decreasing in California, Chemosphere, PMID: 26693645), published in December 2015, was designed to assess the effect of the legislative action that led to the phase out of PBDEs. The study compared PBDEs in breast milk of California women collected at two different time periods, before and after the phase out. The first group of 82 women was recruited in 2003-05 and the second group of 66 women in 2009-11. Overall, PBDEs dropped by 39% between the two time periods. Despite the decrease, 30% of breastfed infants are still exposed to unacceptably high PBDE levels (above the USEPA RfD). For more information on the study, the DTSC Press Release and news stories, click here.
The second study (Guo W, Garner S, Yen S, Petreas M, Park J-S (2016): Temporal changes of PBDE Levels in California house cats and a link to cat hyperthyroidism. Environ Sci & Technol, 50(3), 1510-1518, 2016, PMID: 26699103) published in January 2016, looked at PBDEs and other persistent chemical contaminants in the blood of house cats. In collaboration with local veterinarians, DTSC scientists recruited cats from two time periods: 2008-10 and 2012-13. PBDE levels in the second time period had dropped by half, whereas other chemical contaminants showed no significant changes. The study also showed that PBDE levels were significantly higher in hyperthyroid cats compared to non-hyperthyroid cats. PBDEs have been suspected as a cause of hyperthyroidism in cats.
>Both these studies are consistent with an earlier study where DTSC in collaboration with UCSF first reported dropping levels of PBDEs in the blood of pregnant California women. These results show that regulatory interventions have a demonstrable effect on exposures and that biomonitoring studies are a great tool to assess changes.
A newer study, however (Hurley S, Goldberg D, Nelson D, Guo W, Wang Y, Baek H-Y, Park J-S, Petreas M, Bernstein L, Anton-Culver H, Reynolds P: Temporal Evaluation of Polybrominated Diphenyl Ether (PBDE) Serum Levels in Middle-Aged and Older California Women, 2011−2015, Environ Sci & Technol, DOI: 10.1021/acs.est.7b00565) published in March 2017, showed that PBDE levels may have plateaued and starting to increase. Further biomonitoring to ascertain current trends and determinants of population exposures is warranted. The story was captured in a press release and picked by Newsweek (March 2017).
DTSC and Flame Retardants
In the late 1990s, DTSC scientists were the first to report anomalously high levels of some flame retardants (polybrominated diphenyl ethers, or PBDEs) in the blood and fatty tissues of California women in a study of chemical contaminants as risk factors for breast cancer (Petreas et al, 2003). While no clear association to breast cancer was found (Hurley et al 2011; Petreas et al 2011), the levels of PBDEs were about thirty times higher than what had been recently reported in European studies. Parallel to the findings in human tissues, DTSC scientists identified an exponential increase in levels of PBDEs in harbor seals from the San Francisco Bay: between the late 1980s and the late 1990s, PBDEs had increased by 100 times in seal blubber (She et al, 2002). These findings were corroborated by other scientists and formed the basis for AB 302 (Chapter 205, Statutes of 2003), which limited the use of some PBDEs in products.
DTSC scientists continued their research into flame retardants developing methodologies (Rogers et al, 2004; Bergman et al, 2012; Guo et al, 2013; Guo et al, 2014; Brown et al, 2014; Petropoulou et al, 2014) and reporting their findings in human tissues (Petreas et al 2002; 2003; 2004; 2011; Hooper et al, 2003; 2007; Fischer et al, 2006; She et al, 2007; Kalantzi et al, 2009; Newsome et al, 2010; Park et al, 2011; 2015; Zota et al, 2011; 2013; Chen et al, 2013), in wildlife (Brown et al, 2006; She et al, 2008; Park et al, 2009; 2009; 2011; Holden et al, 2009; Harwani et al, 2011) and in dust (Guo et al, 2012; Whitehead et al, 2013; 2015; Shen et al, 2015).
In 2004-2005 in conjunction with DTSC studies on e-waste and autoshredder waste, DTSC scientists measured PBDEs in the collected samples. The report identified e-waste as the major repository of PBDEs in waste streams, followed by autoshredder waste and sewage sludge and warned of waste management practices that could impact the spread of PBDEs in the environment (Petreas and Oros, 2009).
In April 2013, DTSC was one of the main sponsors of the Sixth International Symposium on Flame Retardants, in San Francisco https://www.bfr2013.com. Former DTSC Director Deborah Raphael gave the opening remarks, and Dr. Gina Solomon, the California Environmental Protection Agency's (Cal/EPA) Deputy Secretary for Science and Health, moderated a panel discussion on science and policy. DTSC staff served as symposium and session chairs and some presented their work. The Symposium Proceedings were co-edited by DTSC staff (Petreas and de Boer, 2014).
In collaboration with the University of California San Francisco, DTSC staff measured decreasing levels of PBDEs in the blood of pregnant women recruited three years apart (Zota et al. 2011; 2013). These findings were consistent with the PBDE phase out following AB 302, and generated media interest. More recently, PBDE levels in breast milk of California women showed a significant decrease, yet levels are still high and almost 30% of the infants would be exposed above the USEPA RfD (Guo et al. 2015).
In 2014, DTSC's Safer Consumer Products Program selected the flame retardants Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP, or Chlorinated Tris) and Tris(2-chloroethyl) phosphate (TCEP)in children's foam-padded sleeping products as its initial "Priority Products". DTSC scientists developed methodologies to measure TDCIPP, TCEP and similar flame retardants in products and dust, as well as their metabolites in human urine.
DTSC has measured PBDEs (and other Persistent Organic Pollutants, POPs) in the blood of Californians as part of the California Biomonitoring Program. DTSC scientists reported very high levels of PBDEs in California firefighters' blood (Park et al. 2015) and the highest levels of PBDEs ever reported in fire station dust (Shen et al, 2015). Newer flame retardants, introduced as PBDE replacements after the phase out, were also prominent in fire station and house dust (Brown et al, 2014).
DTSC scientists continue to investigate flame retardants and have built a reputation as leaders in the field. As the types of flame retardants evolve, DTSC scientists will expand their capabilities to protect public health and the environment.
DTSC Staff Publications on Flame Retardants
For a complete list of ECL publications, please contact Kathleen Jones-Tucker at Kathleen.Jones-Tucker@DTSC.CA.GOV
Common Flame Retardants Used in Furniture
In a 2014 study by Duke University scientists, samples of residential furniture foam were tested, and the major flame retardants identified were OPFRs, followed by BFRs. Information on these major flame retardants is shown below:
TDCIPP, or tris (1,3-dichloro-2-propyl) phosphate, is a chlorinated organophosphate flame retardant that is being used to replace PentaBDE. TDCIPP, which is used as an additive flame retardant in resins, polymers, latexes, and foams, is widely used in the US. In 2012, OEHHA placed TDCIPP on the Prop65 List as a carcinogen.
TCIPP is a chlorinated organophosphate flame retardant very similar in structure to TDCIPP (see above) – it is widely used as an additive flame retardant in resins, polymers, latexes, and foams.
TCEP is a chlorinated organophosphate flame retardant that is being used as a replacement for PentaBDE in foam and furnishings. In 1992, OEHHA placed TCEP on the Prop65 List as a carcinogen. TCEP can also be found as an impurity in the commercial mixture V6.
TPHP is a an aryl phosphate found as a component of Firemaster 550 and other flame retardant formulations added to polyurethane foam.
Polybrominated diphenyl ethers (PBDEs) are members of commercial flame retardant mixtures that have been used for decades in polyurethane foam, furnishings and consumer electronics. Due to concerns over persistence in the environment, ability to accumulate in humans, pets and wildlife, as well as potential toxicity, California restricted the use of PentaBDEs and OctaBDEs in 2004, and the US began a phase out in 2005. For more information on PBDEs, see the ToxFAQs summary created by the US Agency for Toxic Substances and Disease Registry.
Introduced as a replacement of PBDEs, it is a commercial mixture of halogenated compounds (2-ethylhexyl-2,3,4,5-tetrabromobenzoate, or EH-TBB, and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate, or BEH-TEBP), and non-halogenated chemicals (triphenyl phosphate, or TPHP, and mixtures of isopropylated triaryl phosphates).
Flame Retardants in Furniture
In September 2014, Governor Brown signed SB 1019 (Leno) into law, requiring the labeling of upholstered furniture for the presence or absence of flame retardants. This law requires a manufacturer of upholstered furniture sold in California ("covered products") to indicate whether or not the product contains added flame retardant chemicals, by appropriately marking the label affixed to the product.
The law is implemented by the Bureau of Electronic and Appliance Repair, Home Furnishings, and Thermal Insulation (BEARHFTI) of the California Department of Consumer Affairs. According to the new law, BEARHFTI will submit samples of "covered products" to DTSC for testing for the presence of flame retardants. Upon completion of the testing, DTSC will submit analytical results to BEARHFTI.
DTSC has the capability to measure a number of chemical classes of flame retardants in "covered products", including Brominated Flame Retardants (BFRs such as PBDEs, constituents of Firemaster, etc.) and Organophosphate Flame Retardants (OPFRs, such as TDCIPP, TCEP, Triphenyl phosphate, etc.).
Screening Technique for Flame Retardants in ProductsUsing test samples of "covered products", DTSC scientists developed a stepwise approach to screen samples for the presence of Bromine (Br) and Phosphorus (P) in order to limit the number of samples that would require quantitation for specific BFRs and OPFRs, respectively. X-Ray Fluorescence (XRF) is used to screen for the presence of Br and Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES) is used to identify and measure the concentration of P. The same test samples were also analyzed for specific BFRs and OPFRs by gas chromatography - tandem mass spectrometry (GC-MS/MS) to demonstrate the applicability of the screening tests. Liquid Chromatography/Time-of Flight mass spectrometry operated with electrospray ionization (LC/ESI-QTOF) is used to explore and screen for flame retardants not included in the current list of chemicals measured by GC-MS/MS. DTSC scientists will continue to expand the number of chemicals they measure to support BEARHFTI. Newer methodologies for additional flame retardants will be posted as they become available.
This work was captured in: Petreas M, Gill R, Takaku-Pugh S, Lytle E, Parry E, Wang M, Quinn J, Park J-S. “Rapid methodology to screen flame retardants in upholstered furniture for compliance with new California labeling law (SB 1019)”. Chemosphere, 152:353–359, 2016. The journal allows free access to this article until May 5, 2016.
As a state agency serving the public, DTSC is sharing the screening approach and all laboratory methodologies with stakeholders. Since the new screening approach utilizes equipment (ICP-OES, XRF, GC/MS) used by most commercial laboratories specializing in the analysis of environmental samples, product screening can become widely available. Commercial laboratories, however, will need to replicate this approach using their own equipment to validate their methodologies, as sensitivities and selectivities would probably differ. Streamlined, simple and low cost analytical methods can help manufacturers and suppliers have their products tested and correctly labeled, ultimately benefitting the consumer.
The following documents are available to download:
For more information on DTSC's work with Flame Retardants, please contact: firstname.lastname@example.org