[No public or meaningful name is available]

Neurotoxicity

Administrative data

Endpoint:

neurotoxicity: acute oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2011-06-24 to 2011-07-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.6200 (Neurotoxicity Screening Battery)

Deviations:

no

GLP compliance:

yes

Remarks:

FIFRA standards; Code of Federal Regulations (CFR) Title 40, Part 160.

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Boric acid

EC Number:

233-139-2

EC Name:

Boric acid

Cas Number:

10043-35-3

Molecular formula:

H3BO3

IUPAC Name:

Boric acid

Test material form:

other: solution

Details on test material:

- Name of test material (as cited in study report): boric acid
- Substance type: inorganic acid
- Physical state: white, odorless, crystalline solid
- Analytical purity: 99% (56.37% B203; boron oxide)
- Purity test date: 2011-08-24
- Lot/batch No.: 8C20
- Stability under test conditions: stable

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

1% (w/v)

Details on exposure:

The test substance was administered in a vehicle of 1% (w/v) aqueous carboxymethyl cellulose to Group 1and 2 animals at respective dose levels of 0 or 2000 mg/kg.
Experimental endpoints consisted of moribundity/mortality and clinical observations, body weights and body weight gains, functional observation battery and motor activity evaluations, post-fixation brain weights, and gross necropsy and neurohistopathologic observations.

Analytical verification of doses or concentrations:

yes

Frequency of treatment:

single administration

Doses / concentrations

Dose / conc.:

2 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Results and discussion

Effect levels

Dose descriptor:

NOAEL

Remarks:

Neurotoxicity

Effect level:

2 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Remarks on result:

other:

Applicant's summary and conclusion

Conclusions:

Boric acid was not neurotoxic up to 2000 mg/kg bw in rats.

Executive summary:

Boric acid was administered to male and female rats to evaluate the potential neurotoxicity of the test substance following a single oral gavage dose (followed by a 14-day observation period). The test substance was administered in a vehicle of 1 % (w/v) aqueous carboxymethyl cellulose to Group 1 and 2 animals at respective dose levels of 0 or 2000 mg/kg. Experimental endpoints consisted of moribundity/mortality and clinical observations, body weights and body weight gains, functional observation battery and motor activity evaluations, post-fixation brain weights, and gross necropsy and neurohistopathologic observations. Administration of the test substance at 2000 mg/kg resulted in no mortality or adverse clinical signs. Total body weight gain in the boric acid-treated male rats was decreased 16% compared to the control group at the end of the 14-day observation period. Functional observation battery and motor activity evaluations did not show any evidence of neurotoxicity in either sex. No neurohistopathology findings (gross lesions or treatment-related microscopic findings) were observed in either sex. In conclusion, a single oral (gavage) dose of boric acid at a level of 2000 mg/kg to male and female rats was not neurotoxic.