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Brominated flame retardants; Toxicity and ecotoxicity

 

 
Appendix 2 - Data sheet 11. Benzene, ethenyl-, homopolymer, brominated
11.  Benzene, ethenyl-, homopolymer, brominated  
11.1 Identification of the substance  
11.1.1 CAS No. 88497-56-7
11.1.2 EINECS No. Not listed
11.1.3 EINECS Name Not listed
11.1.4 Synonyms Ethenylbenzene homopolymer, brominated

Brominated polystyrene

JM-631, K0768A and S-346 are sample designations for Pyro-Chek 68PB type materials from Ferro Corporation. K0768A is characterised by a molecular weight of 200,000 and a melting point of approx. 190°C (3)

KH97, KN707 and LD-544 are sample designations for Pyro-Chek LM type materials from Ferro Corporation. KH97 and LD-544 are identical. In Pyro-Chek LM. Lot no. OV-779W the following impurities were identified: ethylene dichloride (0.047%, CAS No. 107-06-2) and water (0.020%) (6)
11.1.5 Molecular Formula (C8HxBry)z (x = 5-6, y = 2-3, z = 4-100)
11.1.6 Structural Formula Structural formula of 88497-56-7
11.1.7 Known uses Used as a flame retardant, melt-blendable (at approx. 180°C) additive to polymeric products including acrylonitrile-butadiene-styrene products, polyethylene (high density), polyamide, polybutylene terephthalate, and others, and typically in conjunction with antimony oxide (16)
11.1.8 EU Classification Not included in Annex I
 
11.2 Physico-chemical Characteristics  
11.2.1 Physical Form Typically fine white to slight off-white powder with odourless or slight aromatic odour. Particles may include portion below 10 mm diameter (16)

JM-631: Fine, beige powder (8) (IBT)

KH97: Grey amorphous powder(2)

LD-544: Tan powder (11)

Pyro-Chek LM: Light orange powder (10)

Pyro-Chek LM (sample OV-779W): Beige powder (9)
11.2.2 Molecular Weight 1,000 - 200,000; typically 750-1,500 (16)
11.2.3 Melting Point/range (°C) No data were available
11.2.4 Boiling Point/range (°C) No data were available
11.2.5 Decomposition Temperature (°C) No data were available
11.2.6 Vapour Pressure (Pa (°C)) 2.0 x 10-5 (20, 16)
11.2.7 Relative Density (D420) 2.1 (16)
11.2.8 Vapour Density (air=1) No data were available
11.2.9 Conversion Factor (1011 hPa at 25 °C) No data were available
11.2.10 Solubility Water: insoluble

Benzene: 780 g/l

Acetone: 580 g/l  (16)
11.2.11 Partition Coefficient (log P ow) No data were available
11.2.12 Flammability No data were available
11.2.13 Explosivity No data were available
11.2.14 Oxidising properties No data were available
 
11.3 Toxicological Data  
11.3.1 Observations in humans No data were available
11.3.2 Acute Toxicity  
11.3.2.1 Oral JM-631. Oral LD50, rats: > 15,380 mg/kg (8) (IBT) 

Pyro-Chek LM. Oral LD50, rats: > 5,000 mg/kg (7)
11.3.2.2 Dermal Oral LD50, rabbits: > 3,038 mg (JM-631)/kg. No systemic toxicity was noted; but the test material was moderately irritating to the skin (4)(IBT)
11.3.2.3 Inhalation JM-631. Dust inhalation LC50, rats: >1.92 mg/l/4 hours. Ten Charles River rats were exposed in a whole-body-exposure chamber to atmospheric dust concentration 1.92 mg/l (max attainable). 39.7% of the particles were less than 6 microns, and another 39.7% were within the range 6-10 microns. The only exposure related sign was red nasal discharge in 4 rats on day 1 of the 14 day observation period (5) (IBT). 

Pyro-Chek LM. Dust inhalation LC50, rats: >5.25 mg/l/4 hours. Ten Charles River rats were exposed in a whole-body-exposure chamber to atmospheric dust concentration 5.25 mg/l (mean gravimetric concentration). 96.5% of the particles were less than 1.01 microns, and the mass median aerodynamic diameter was determined to be 3.8 microns. The only exposure related sign was body weight loss in 4 animals within the 14 day observation period (6, 15)
11.3.2.4 Other Routes No data were available
11.3.2.5 Skin Irritation Pyro-Chek LM. Grading of dermal reactions (mean of the 24 and 72 hours examinations/max. score) (14):
Erythema and eschar:   0.17/4
Oedema:                     0.00/4
11.3.2.6 Eye Irritation JM-631. Grading of ocular lesions (mean of the 24, 48 and 72 hours examinations/max. score) (8) (IBT):
Cornea opacity:             0.00/4
Iris:                                0.00/2
Conjunctivae, erythema: 0.61/3
Conjunctivae, oedema:   0.00/4

Pyro-Chek LM. Grading of ocular lesions (mean of the 24, 48 and 72 hours examinations/max. score) (13):

Cornea opacity:              0.22/4
Iris:                                 0.00/2
Conjunctivae, erythema:  0.61/3
Conjunctivae, oedema:    0.17/4
11.3.2 7 Irritation of Respiratory Tract No data were available
11.3.2.8 Skin Sensitisation Pyro-Chek LM was tested in a guinea pig maximisation test. After the challenge (and re-challenge) with Pyro-Chek LM notably greater dermal reactions (grade 2 erythema with oedema) were observed in 2/10 test animals at the 24 and 48 hour scoring interval. The result indicated a weak dermal sensitisation (6)
11.3.2.9 Sensitisation by Inhalation No data were available
11.3.3 Subchronic Toxicity  
11.3.3.1 Oral No data were available
11.3.3.2 Inhalation No data were available
11.3.3.3 Dermal No data were available
11.3.4 Chronic Toxicity and Carcinogenicity No data were available
11.3.5 Mutagenicity  
11.3.5.1 Gene Mutation JM-631 was tested for mutagenicity in five Salmonella typhimurium strains (TA-98, TA-100, TA-1535, TA-1537, and TA-1538) in the presence and absence of Aroclor-induced rat liver S9. These tests were all negative (1). 

K0768A was tested negative for mutagenicity in five Salmonella typhimurium strains (TA-98, TA-100, TA-1535, TA-1537, and TA-1538) in the presence and absence of Aroclor-induced rat liver S9. (3)

KH97 was generally negative in a test for mutagenicity in five Salmonella typhimurium strains (TA-98, TA-100, TA-1535, TA-1537, and TA-1538) in the presence and absence of Aroclor-induced rat liver S9; but a significant increase in the number of point mutations was noted in strain TA-1537 without S-9 mix.(2) 

LD-544 was tested negative for mutagenicity in five Salmonella typhimurium strains (TA-98, TA-100, TA-1535, TA-1537, and TA-1538) in the presence and absence of Aroclor-induced rat liver S-9 mix.(11) 

Pyro-Chek LM sample #NF556W was tested for mutagenicity in five Salmonella typhimurium strains (TA-98, TA-100, TA-1535, TA-1537, and TA-1538) in the presence and absence of Aroclor-induced rat liver S-9 mix. The test material was positive in strains TA-98 and TA-100, only in the absence of S-9 mix (10) 

Pyro-Chek LM sample #NF 556 WRD was tested for mutagenicity in five Salmonella typhimurium strains (TA-98, TA-100, TA-1535, TA-1537, and TA-1538) in the presence and absence of Aroclor-induced rat liver S-9 mix. The test material was positive in strain TA-100, only in the absence of S-9 mix (12). 

Different samples were tested in Salmonella typhimurium strain TA-100 in the absence of S-9 mix. Some were positive. The identification of the mutagenic species was not possible although it appeared to be an artefact of the fractional precipitation procedures (9).

Pyro-Chek LM (sample OV-779W) was tested for mutagenicity in five Salmonella typhimurium strains (TA-98, TA-100, TA-1535, TA-1537, and TA-1538) in the presence and absence of Aroclor-induced rat liver S-9 mix. The test material was negative in all strains tested (9).
11.3.5.2 Chromosome Abnormalities No data were available
11.3.5.3 Other Genotoxic Effects No data were available
11.3.6 Reproductive Toxicity, Embryotoxicity, and Teratogenicity  
11.3.6.1 Reproductive Toxicity No data were available
11.3.6.2 Teratogenicity No data were available
11.3.7 Other Toxicity Studies No data were available
11.3.8 Toxicokinetics No data were available
 
11.4 Ecotoxicity No data were available
 
11.5 Environmental Fate No data were available
 
11.6 Environmental Concentrations No data were available
 
11.7 Conclusion  
11.7.1 Health Assessment Sufficient toxicological data were identified for a health assessment of brominated polystyrene. Most of the data were found in documents submitted to the U.S. EPA. These documents contain study reports of tests performed in the late nineteen seventies, and only a few is performed according presently, generally accepted international guidelines and Good Laboratory Practice. A couple of the tests were conducted by Industrial Bio-Test Laboratories, a concern later found to have submitted many flawed or fraudulent reports on its procedures and results. No data on subchronic toxicity, chronic toxicity, carcinogenicity or reproductive toxicity were identified. No chromosome aberration tests or any other mutagenicity tests except the gene mutation tests were found. No data on humans were identified.

Brominated polystyrene is not a chemically well defined substance and the molecular formula, (C8HxBry)z (x = 5-6, y = 2-3, z = 4-100), indicate the existence of a range of different molecules. The high molecular weight of the molecular material of the molecular material indicate a low potential for transport to the systemic circulation, and the associated toxicity is considered very low.

Monomers, solvents and other impurities may account for the mutagenic potential found in some gene mutation assays. The only impurity listed, ethylene dichloride (CAS No. 107-06-2), occurred at very low concentrations, but it is a well known potential carcinogen (Carc2; R45).
11.7.2 Environmental Assessment No ecotoxicity or environmental fate data were available for environmental assessment.
 
11.8 References 1. Activity of JM-631 in the salmonella microsomal assay or bacterial mutagenicity (final report) with cover letter dated 030990. EPA/OTS; Doc #86-900000143 1990. NTIS/OTS0522214.

2. Activity of KH97 in the salmonella/microsomal assay for bacterial mutagenicity (final report) with attachments and cover letter dated 030990. EPA/OTS; Doc #86-900000146 1990. NTIS/OTS0522217.

3. Activity of KO768a in the salmonella/microsomal assay for bacterial mutagenicity (final report) with cover letter dated 030990. EPA/OTS; Doc #86-900000144 1990. NTIS/OTS0522215.

4. Acute dermal toxicity study with JM-631 in albino rabbits with cover letter dated 030990. EPA/OTS; Doc #86-900000142 1990. NTIS/OTS0522213.

5. Acute dust inhalation toxicity study with JM-631 in albino rats with cover letter dated 030990. EPA/OTS; Doc #86-900000141 1990. NTIS/OTS0522212.

6. Acute inhalation toxicity in rats with Pyro-Chek LM & a dermal sensitization study in guinea pigs with Pyro-Chek LM - maximization design (final reports) w-cover letter dated 06209. EPA/OTS; Doc #86-900000460 1990. NTIS/OTS0524339.

7. Acute oral toxicity study in rats with Pyro-Chek LM (final report) with cover letter dated 030990. EPA/OTS; Doc #86-900000153 1990. NTIS/OTS0522224.

8. Acute toxicity studies with JM-631 (acute oral & eye irritation) with cover letter dated 030990. EPA/OTS; Doc #86-900000140 1990. NTIS/OTS0522211.

9. Letter from Ferro Corp to US EPA submitting two 8d studies on tribrominated polystyrene with attachments. EPA/OTS; Doc #86-900000449 1990. NTIS/OTS0526025.

10. Mutagenicity test on Pyro-Chek LM, sample #NF556W in the Ames Salmonella/microsome reverse mutation assay (final report) with cover letter dated 030990. EPA/OTS; Doc #86-900000149 1990. NTIS/OTS0522220.

11. Mutagenicity evaluation of LD-544 in the Ames Salmonella/microsome plate test (final report) with cover letter dated 030990. EPA/OTS; Doc #86-900000148 1990. NTIS/OTS0522219.

12. Mutagenicity test on Pyro-Chek LM, samples #NF 556 WRD in the Salmonella/mammalian-microsome reverse mutation assay (Ames test) (final report) w-attachment & letter dated 030990. EPA/OTS; Doc #86-900000150 1990. NTIS/OTS0522221.

13. Primary eye irritation study in rabbits with Pyro-Chek LM with attachments and cover letter dated 030990. EPA/OTS; Doc #86-900000151 1990. NTIS/OTS0522222.

14. Primary skin irritation study on rabbits with Pyro-Chek LM (final report) with cover letter dated 030990. EPA/OTS; Doc #86-900000152 1990. NTIS/OTS0522223.

15. Acute inhalation toxicity study in rats with Pyro-Chek LM (amended final report) with cover letter dated 053191 and attachment. EPA/OTS; Doc #86-910000862 1991. NTIS/OTS0530450.

16. Leber AP. Flame Retardants. Chapter 41: Clayton GD, Clayton FE, Editors. Patty's Industrial Hygiene and Toxicology. 4th edition. Vol. 2. New York: John Wiley & Sons, Inc., 1994: 4390-3.