2-ethylhexyl-2,3,4,5 tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 3,4,5,6-tetrabromophthalate (TBPH)- information sheet

Benzoic acid, 2,3,4,5-tetrabromo-, 2-ethylhexyl ester
CAS Registry Number 183658-27-7

1,2-Benzenedicarboxylic acid, 3,4,5,6-tetrabromo-, bis(2-ethylhexyl) ester
CAS Registry Number 26040-51-7

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  • The Government of Canada prepared a state of the science (SOS) report to review the current science on TBB and TBPH and provide an updated analysis of potential for harm to Canadians and the environment.
  • Under the Canadian Environmental Protection Act, 1999 (CEPA 1999), the risk posed by a substance is determined by considering both its hazardous properties (its potential to cause adverse human health or ecological effects) and the amount of exposure there is to people and the environment. A substance may have hazardous properties; however, the risk to human health or to the environment may be low depending upon the level of exposure.
  • At current levels of exposure, TBB and TBPH are not considered harmful to human health or the environment.

About these substances

  • This SOS report focuses on 2 of 10 substances referred to collectively under the Chemicals Management Plan (CMP) as the Certain Organic Flame Retardants Substance Grouping which includes organic substances having similar function: application to materials to slow the ignition and spread of fire. The substances addressed in this report are benzoic acid, 2,3,4,5-tetrabromo-, 2-ethylhexyl ester, and 1,2-benzenedicarboxylic acid, 3,4,5,6-tetrabromo, bis(2-ethylhexyl) ester also referred to as 2-ethylhexyl-2,3,4,5 tetrabromobenzoate or TBB, and bis(2-ethylhexyl) 3,4,5,6-tetrabromophthalate or TBPH, respectively.
  • TBB and TBPH do not occur naturally in the environment.
  • According to information gathered by the Government, these substances are used in Canada primarily as additive flame retardants in polyurethane foams (for example, in mattresses, pillows and cushions) or as plasticizers.

Human and ecological exposures

  • The main sources of exposure for the general population in Canada are expected to be from the environment (for example, from air, dust, soil, and water), food, including breast milk, and from the use of products available to consumers, such as foam-containing furniture.
  • This assessment took into consideration the results of human biomonitoring studies, which is the measurement of substances in blood, urine or breast milk. Finding the substance in the body does not necessarily mean that it is causing harm. Harmful effects will depend on the levels and the properties of the substances. The information on measured levels in humans is important to estimating exposure to Canadians.
  • TBB and TBPH may be released to the Canadian environment through wastewater as a result of industrial processing activities.

Key health and ecological effects (hazard)

  • To identify health hazard information, national and international reports of data were reviewed.
  • The important or ‘critical’ effects considered from exposure to TBB or TBPH are effects on the reproductive system.
  • TBB and TBPH have demonstrated toxicity to aquatic organisms at low concentrations.


  • Based upon a comparison of levels to which Canadians may be exposed to TBB and TBPH and the levels associated with health effects, the risk to human health from these substances is considered to be low.
  • Considering the information available, there is currently a low potential for harm to the environment from TBB and TBPH.
  • Estimated levels of exposure of TBB and TBPH are not indicative of harm to the environment or to human health; however there may be concerns if import and use quantities were to increase in Canada.
  • The Government of Canada published the Final State of the Science Report for TBB and TBPH on May 11, 2019.

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