Dipotassium 3,4,5,6-tetrabromophthalate

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

90 days

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Although testing was performed on the chloro derivative and not bromo, the use of this for read-across has been justified in other REACH dossiers on the basis that the chloro derivative will be more biologically active. The justification is driven by the need to avoid unecessary animal testing.
The anhydride will quickly hydrolyse to the acid form once ingested and will behave in the same way as salts that will dissociate under biological conditions.
The source data is from peer-reviewed US National Toxicity Program research.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1993

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tetrachlorophthalic anhydride

EC Number:

204-171-4

EC Name:

Tetrachlorophthalic anhydride

Cas Number:

117-08-8

Molecular formula:

C8Cl4O3

IUPAC Name:

Tetrachlorothphalic anhydride

Test animals

Species:

mouse

Strain:

B6C3F1

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

90 days

Frequency of treatment:

Dosed for 5 days a week

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

94 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

187 mg/kg bw/day (nominal)

Doses / concentrations 4

Dose / conc.:

375 mg/kg bw/day (nominal)

Doses / concentrations 5

Dose / conc.:

750 mg/kg bw/day (nominal)

Doses / concentrations 6

Dose / conc.:

1 500 mg/kg bw/day (nominal)

No. of animals per sex per dose:

10 males and 10 females

Control animals:

yes, concurrent vehicle

Examinations

Observations and examinations performed and frequency:

Daily clinical observations
Weighed weekly

Sacrifice and pathology:

Necropsies on all animals

Other examinations:

Clinical pathology performed in the 94, 375 and 1500 mg/kg groups on days 6, 20, and at the end of the study.
Hematology performed in all animals at end of study.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One female died, as a result of a dosing accident.

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Description (incidence and severity):

Sperm morphology evaluations were performed from the 0, 94, 375, and 750 mg/kg dose groups.
Vaginal cytology evaluations were performed from the 0, 94, 375, and 1500 mg/kg dose groups
For the 7 days prior to sacrifice, the vaginal vaults of the females of each species and dose group were lavaged, and the aspirated lavage fluid and cells were stained with Toluidine Blue. Relative numbers of leukocytes, nucleated epithelial cells, and large squamous epithelial cells were determined and were used to ascertain estrous cycle stage (i.e., diestrus, proestrus, estrus, or metestrus).
Sperm morphology was evaluated at necropsy in the following manner. The right epididymis was isolated and weighed. The tail of the epididymis (cauda epididymis) was then removed from the epididymal body (corpus epididymis) and weighed. Test yolk (rats) or Tyrode's buffer (mice) was applied to slides, and a small incision was made at the distal border of the epididymal tail. The sperm effluxing from the incision were dispersed in the buffer on the slides and the numbers of motile and nonmotile spermatozoa were counted for 5 fields per slide.
Following completion of sperm motility estimates, each right cauda epididymis was placed in buffered 0.9% saline solution. Cauda were gently minced, and the tissue was incubated in the saline solution and then heat fixed at 65°C. Sperm density was then determined microscopically with the aid of a hemacytometer.

Effect levels

Dose descriptor:

NOAEL

Effect level:

ca. 1 500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Target system / organ toxicity

Critical effects observed:

yes

Lowest effective dose / conc.:

375 mg/kg bw/day (nominal)

System:

urinary

Organ:

kidney

Treatment related:

yes

Dose response relationship:

yes

Relevant for humans:

not specified

Applicant's summary and conclusion

Conclusions:

The toxicity to mice appears to be significantly lower than to the rat
Although the work was performed on the tetrachloro derivative instead of tetrabromo, the effects observed would not have been due to the presence of chlorine ions and can be attributed to the phthalic acid. The anhydride use in the test would quickly form as the acid on ingestion.
The substance is considered a valid read-across surrogate as the potassium salt will dissociate and behave in the same was as the acid form when exposed to biological media.