Cobalt, borate 2-ethylhexanoate complexes

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-12-10 to 2013-03-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Version / remarks:

2008-10-03

Deviations:

no

GLP compliance:

yes

Test type:

up-and-down procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt, borate 2-ethylhexanoate complexes

EC Number:

295-032-7

EC Name:

Cobalt, borate 2-ethylhexanoate complexes

Cas Number:

91782-60-4

Molecular formula:

(C8H15O2)3BO3Co3

IUPAC Name:

({1,5-bis[(2-ethylhexanoyl)oxy]-2,4-dioxa-3-bora-1,5-dicobaltapentan-3-yl}oxy)cobaltio 2-ethylhexanoate

Test material form:

other: solid

Details on test material:

- Name of test material (as cited in study report): C42.9-PTL Cobalt Borate Octoate
- Physical state: solid blue/purple
- Stability under test conditions: test substance was expected to be stable for the duration of testing
- Storage condition of test material: stored at room temperature, in a tightly closed container and away from heat and sources of ignition
- Solubility: soluble in hydrocarbons

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories, Inc.
- Age at study initiation: 8 - 11 weeks
- Weight at study initiation: 176 - 217 grams
- Fasting period before study: prior to each dosing, experimentally naive rats were fasted overnight by removing the feed from their cages.
- Housing: the animals were singly housed in suspended stainless steel caging with mesh floors, which conform to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Enrichment (e.g. toy) was placed in each cage. Litter paper was placed beneneath the cage and was changed at least three times per week. Feed was replaced approximately 3 - 4 hours after dosing.
- Diet ( ad libitum, except during fasting): Harlan Teklad Global 16% Protein Rodent Diet® #2016
- Water (ad libitum): filtered tap water
- Acclimation period: 6 - 26 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19 - 23°C
- Relative humidity: 16 - 52%
- Air changes: 13 and 14 air changes/hour
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

DOSAGE PREPARATION:
The test substance was administered as a 45% w/w mixture in distilled water. Preliminary solubility testing conducted by the laboratory indicated mixtures in excess of 45% (i.e. 50%-80%) were too viscous to be administered properly.

Individual doses were calculated based on the initial body weights, taking into account the density (determined by the laboratory) and concentration of the test mixture.

initially, a single animal received a limit dose of 5000 mg/kg. Due to mortality of this animal a Main Test was conducted. For the Main Test, the test substance was administered in sequence to the animals as can be seen in table 1 in the field "Any other information on materials and methods incl. tables" below. The decision to proceed with the next animal was based on survival of the previous animal following dosing. Dose progressions and stopping criteria were determined using a statistical program

Doses:

175, 550, 1750 and 5000 mg/kg

No. of animals per sex per dose:

175 mg/kg: 1 animal
550 mg/kg: 4 animals
1750 mg/kg: 6 animals
5000 mg/kg: 4 animals

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: individual body weights of the animals were recorded prior to test substance administration (initial) and again on Days 7 and 14 (termination) following dosing or after death. The animals were observed for mortality, signs of gross toxicity, and behavioural changes during the first several hours post-dosing and at least once daily thereafter for 14 days after doing or until death occurred.
- Necropsy of survivors performed: yes
Surviving rats were euthanized via CO2 inhalation at the end of the 14-day observation period. Gross necropsy were performed on all decendents and euthanized animals. Tissues and organs of the thoracic and abdominal cavities were examined.

Statistics:

The Acute Oral Toxicity (Guideline 425) Statistical Program (Weststat, version 1.0, May 2001) was used for all data analyses including: dose progression selections, stopping criteria determinations and/or LD50 and confidence limit calculations.

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

2 210 mg/kg bw

Based on:

test mat.

Remarks on result:

other: (based on maximum likelihood); approx. 95% profile-likelihood based confidence interval of 960.4 mg/kg lower to 9430 mg/kg (upper)

Mortality:

- 175 mg/kg dose level (1 animal):
This animal survivied during the study.
- 550 mg/kg dose level (4 animals):
All animals survived during the study.
- 1750 mg/kg dose level (6 animals):
Three females died within three days of test substance administration.
- 5000 mg/kg dose level (5 animals):
Four animals died within seven days of test substance administration, including one animal euthanised for humane reasons on Day 7.

Clinical signs:

other: 175 mg/kg dose level (1 animal): Apart from the animal exhibiting reduced fecal volume on Day 1, there were no other signs of gross toxicity, adverse pharmacologic effects, or abnormal behaviour. - 550 mg/kg dose level (4 animals): All animals appeared ac

Gross pathology:

175 mg/kg dose level (1 animal):
No gross abnormalities were noted for this animal when necorpsied at the conclusion of the 14-day observation period.
- 550 mg/kg dose level (4 animals):
No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.
- 1750 mg/kg dose level (6 animals):
Gross necropsy of the decedents revealed discolouration of the intestines and distention of the stomach and/or intestines. No gross abnormalities were noted for the euthanised animals when necropsied at the conclusion of the 14-day observation period.
- 5000 mg/kg dose level (5 animals):
Gross necropsy of the decedents revealed discolouration and/or distention of the intestines and/or stomach. no gross abnormalities were noted for the euthanised animal when necorpsied at conclusion of the 14-day observation period.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

LD50: 2210 mg/kg (based on maximum likelihood) (approx. 95% profile-likelihood based confidence interval of 960.4 mg/kg lower to 9430 mg/kg (upper).
According to the EC-Regulation 1272/2008 and subsequent regulations, the test item is not classified.