in Environmental Exposures and Health
Wonder what is being used in polyurethane foam as a flame retardant now that production of certain forms of PBDE have been banned?
With numerous collaborators, we have published two papers on new and alternative flame retardants that we found in the indoor environment:
- Stapleton HM, Allen JG, Kelly S, Konstantinov A, Klosterhaus S, Watkins D, Mcclean MD, Webster TF. Alternate and New Brominated Flame Retardants Detected in US House Dust. Environ Sci Technol 2008; 42 (18), 6910–6916. [Online 23 July 2008]. Abstract and full text (for ES&T subscribers): doi: 10.1021/es702964a. See also the accompanying story by Kellyn Betts.
- Stapleton HM, Klosterhaus S, Eagle S, Fuh J, Meeker JD, Blum A, Webster TF. Detection of Organophosphate Flame Retardants in Furniture Foam and U.S. House Dust. Environ Sci Technol 2009; 43:7490–7495. [Online 13 August 2009]. Abstract and full text (for ES&T subscribers): DOI: 10.1021/es901401. See also the accompanying story Discontinued pajama flame retardant detected in baby products and house dust.
So far, we have found:
- Firemaster 550, a replacement for PentaBDE
- TDCPP ('chlorinated tris'), another replacement for PentaBDE, as well as other organophosphate flame retardants (OPFRs)
- DPDPE
- BTBPE
Firemaster 550
Perhaps the most interesting finding were some unidentified substances which turned out to be 2,3,4,5-tetrabromo-ethylhexylbenzoate (TBB) and (2-ethylhexyl)tetrabromophthalate. While TBPH has been used in the past as a flame retardant in neoprene and PVC. Together they are used in Firemaster 550 (FM550), a fire retardant being used as a replacement for pentaBDE in polyurethane foam. This component of FM550 is listed on the Material Safety Data Sheet as a trade secret. In other words, although it can be produced in large amounts and put in your furniture, neither consumers nor environmental scientists are informed of its identity.
Pictured at left is a recently identified component of Firemaster 550, (2-ethylhexyl)tetrabromophthalate (TBPH). It is a brominated form of the phthalate DEHP.
2,3,4,5-tetrabromo-ethylhexylbenzoate (TBB) is the other BFR component of FM550. It is similar to TBPH but with one whole chain missing.
Because of the difficulty of obtaining data on these compounds, we will attempt to post here either links or documents that we find:
- (2-ethylhexyl)tetrabromophthalate (TBPH) is also called 3,4,5,6-tetrabromo-diethyhexylphthalate, phthalic acid tetrabromo bis 2-ethylhexyl ester and 1,2-benzenedicarboxylic acid, 3,4,5,6-tetrabromo-, bis(2-ethylhexyl) ester. The confusion of names is the reason for the all important CAS numbers: CAS # 26040-51-7.
- 2,3,4,5-tetrabromo-ethylhexylbenzoate (TBB), CAS # 183658-27-7, is a variety of octyl tetrabromobenzoate (OTB).
- Material Safety Data Sheet (MSDS) for FM550: download. Component A, listed as TS (trade secret) is a mixture of TBPH and TBB as discussed in our paper. Note that the MSDS does not provide the CAS number for these compounds.
- High Production Volume (HPV) information on TBPH. There are a couple options here:
- 1) Go to the USEPA's High Production Volume Information System (HPVIS) webpage for this compound. Download the information that you want, e.g., physical-chemical data, toxicity.
- 2) Download the following document from another part of the HPV website by clicking here: Health and Environmental Horizons 2004. High Production Volume (HPV) Challenge Program Test Plan for Phthalic Acid Tetrabromo Bis 2-Ethylhelxyl Ester (CAS#26040-51-7). Prepared for the Brominated Phthalate Ester Panel, American Chemical Council. July 1, 2004. [2.5 MB].
- The report of the USEPA's Furniture Flame Retardancy Partnership entitled Environmental Profiles of Chemical Flame-Retardant Alternatives for Low-Density Polyurethane Foam (2005). Note that Proprietary compounds F and H are the halogenated aromatic esters used in FM550, i.e., they are TBPH and TBB (but not necessarily in that order!). You may be surprised at the number of times the words "No data available" appear.
- Interestingly, a 2006 Consumer Products Safety Commission report identifies FM550 as containing octyl tetrabromobenzoate (OTB); it does not mention TBPH. M. Babich. CPSC staff preliminary risk assessment of flame retardant (FR) chemicals in upholstered furniture foam. U.S. Consumer Product Safety Commission, Bethesda, MD. 2006. download (5.6 MB)
If all of this seems both crazy and confusing, welcome to the club.
TDCPP (chlorinated tris): A replacement for pentaBDE
Another PentaBDE replacement is TDCPP, also known as chlorinated tris (CAS# 13674-87-8). Along with our collaborators, we reported finding TDCPP and other organophosphate flame retardants (OPFRs) in consumer products and house dust.
TDCPP, along with its more famous cousin (brominated tris), were used for a while in kids' pajamas before being removed about 30 years ago. For the 1978 paper on TDCPP in Science, look here.
DBDPE
Decabromodiphenyl ethane (DBDPE) is another new flame retardant we found in house dust in collaboration with Heather Stapleton. It is apparently a replacement for DecaBDE. Note that it differs in structure from BDE209, the major component of DecaBDE solely by replacing the central oxygen (ether) by an ethane.
BTBPE
Bis(2,4,6,-tribromphenoxy)ethane (BTBPE) is another new flame retardant we found in house dust in collaboration with Heather Stapleton. It may be a replacement for OctaBDE.
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