Potassium chromate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The EU RAR summarises the findings of a number of studies performed to various guidelines. However the resulys of the studies are consistent.

Data source

Reference

Reference Type:

other: EU RAR

Title:

European Union Risk Assessment Report: chromium trioxide, sodium chromate, sodium dichromate, ammonium dichromate, potassium dichromate

Author:

European Chemicals Bureau

Year:

2005

Bibliographic source:

3rd Priority List; Volume 53

Materials and methods

Principles of method if other than guideline:

The EU RAR reports the findings of a number of different studies.

GLP compliance:

no

Remarks:

One of the studies is GLP-compliant

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Potassium dichromate

EC Number:

231-906-6

EC Name:

Potassium dichromate

Cas Number:

7778-50-9

Molecular formula:

Cr2H2O7.2K

IUPAC Name:

sodium dichromate

Details on test material:

The test substance was purchased from Aldrich Chemical Corp. and provided by the NTP through Research Triangle Institute (RTI), (Research Triangle Park, North Carolina). All bulk chemical analyses and test formulations analyses were conducted by RTI. Prior to the initiation of dosing, two 5 g samples of the bulk test article were collected into amber glass bottles with Teflon coated lids, sealed and stored in the freezer protected from light for possible analysis. A bulk test article of 5 g was collected and sent to RTI for purity and stability testing within 30 days of receipt. The compound was analyzed at RTI upon receipt from the vendor, Aldrich and the relative purity was determined to be approx. 99%, based on potassium content. The identity and purity of the compound was confirmed by infrared spectrometry and inductively coupled plasma emission spectrometry (ICP). A bulk chemical reanalysis was sent on May 9, 1995 and analyzed on August 16, 1995. The relative purity was determined to be 98.5% based on potassium content.

Test animals

Species:

mouse

Strain:

other: various

Administration / exposure

Route of administration:

oral: drinking water

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Various study designs

Duration of treatment / exposure:

Various study designs

Frequency of treatment:

Various study designs

Duration of test:

Various study designs

No. of animals per sex per dose:

Various study designs

Results and discussion

Results: maternal animals

Effect levels (maternal animals)

Remarks on result:

other: See "Any other information on results incl. tables" below.

Results (fetuses)

Effect levels (fetuses)

Remarks on result:

other: See "Any other information on results incl. tables" below.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Foetotoxicity, including post-implantation losses, was observed in the mouse following the administration of potassium dichromate in drinking water during gestation (days 0-19). Significant developmental effects occurred at the lowest dose level tested, 60 mg/kg bw/d (20 mg Cr(VI)/kg bw/d) in the absence of maternal toxicity. Qualitatively similar results were obtained in another study in which (350 mg/kg bw/d) potassium dichromate (125 mg Cr(VI)/kg bw/d) was administered for a shorter period, on days 6-14 of gestation. In a pregestational study in female mice, fetotoxic effects were seen starting from the lowest dose level tested, 250 ppm (63 mg/kg bw/d (22.1 mg Cr(VI)/kg bw/d)) potassium dichromate. Significant levels of total chromium were found in treated animals at sacrifice.

Applicant's summary and conclusion

Conclusions:

The results of these studies indicate that potassium dichromate is a developmental toxin following administration to the mouse. Given the comparable toxicokinetics, similar toxicity is assumed for the other water-soluble Cr (VI) compounds in this group.

Executive summary:

The results of developmental toxicity studies of various designs and reliabilities performed in the mouse with potassium dichromate show that this compound is a developmental toxin; similar activity is assumed for the other compounds in this group.