Hydrogen fluoride

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published study.

Data source

Reference

Reference Type:

publication

Title:

Evaluation of intravenous magnesium sulfate for the treatment of hydrofluoric acid burns

Author:

Cox RD & Osgood KA

Year:

1994

Bibliographic source:

Clinical toxicology, 32(2): 123-136

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Investigation of the efficacy of treatments for dermal exposure to HF

GLP compliance:

no

Test type:

other: single dose application

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hydrogen fluoride

EC Number:

231-634-8

EC Name:

Hydrogen fluoride

Cas Number:

7664-39-3

Molecular formula:

FH

IUPAC Name:

hydrogen fluoride

Details on test material:

Hydrogen fluoride was obtained from Fischer Scientific, and was 49% by volume.

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

not specified

Details on test animals or test system and environmental conditions:

New Zealand white rabbits weiging 4.5-6kg. A 12 hour light/dark schedule was used, and rabbits were fed a standard commercial diet. Procedures and animal handling conformed to the guidelines of the American Association for the Accreditation for Laboratory Animal Care. Animals were randomly assigned to groups by lot selection.

Administration / exposure

Type of coverage:

open

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

Exposure was carried out under general anaesthesia. The dorsal surface of the rabbits was shaved and washed with soap and water (during preliminary studies it was found that rabbits have a protective oil on the skin that must be washed off to maximise reproducibility of burns). Four cylindrical plastic disks were placed on either side of the spine over the paraspinal musculature. The disks had an internal surface area of 0.9 square cm. The external surface of each disk was coated with a thick layer of petroleum jelly to help provide a seal. 100µl hydrogen fluoride was pipetted into each disk and left in place for 5 minutes. Mild pressure was used to keep the disks in placec and minimise leakage. The disks were removed after 5 minutes and the area irrigated with tap water for 5 minutes.

Duration of exposure:

5 minutes.

Doses:

100µl; 49% hydrogen fluoride.

No. of animals per sex per dose:

34 rabbits.

Control animals:

other: The study was comparing the effects of different treatments on burn healing, therefore the controls were the rabbits that were exposed to HF and received no treatment (n=34).

Details on study design:

Burns were evaluated until fully recovered; wounds were observed daily for the first 3 days, every other day between days 4 and 10, then every 2-3 days until complete wound healing. Following complete wound healing animals were euthanased and wounds were dissected.

Statistics:

Not applicable.

Results and discussion

Preliminary study:

Not applicable.

Mortality:

No mortality was observed.

Clinical signs:

other: No clinical signs were observed.

Gross pathology:

All burns were full dermal burns. 59% lesions progressed beneath the platysma layer.

Other findings:

The exposure sites were initially a pale-blanched colour. Several hours later a purpuric ring evolved around the blanched area, which persisted for several days. Scar areas were 50% larger than the original 1 square cm exposure site. The average healing time for burns was 37.4days (standard deviation 9.1days).

Any other information on results incl. tables

Application of 100 µl 49% hydrogen fluoride to the dorsal surface of rabbits (4 disks on the back each with an area of 1cm²) for 5 minutes resulted in full dermal burns taking an average of 37.4 days (SD 9.1 days) to heal. 59% burns progressed beneath the platysma layer.

Applicant's summary and conclusion

Conclusions:

Application of 100µl 49% hydrogen fluoride to the dorsal surface of rabbits (4 disks on the back each with an area of 1cm2) for 5 minutes resulted in full dermal burns taking an average of 37.4days (SD 9.1days) to heal. 59% burns progressed beneath the platysma layer.

Executive summary:

Application of 100µl 49% hydrogen fluoride to the dorsal surface of rabbits (4 disks on the back each with an area of 1cm²) for 5 minutes resulted in full dermal burns taking an average of 37.4days (SD 9.1days) to heal. 59% burns progressed beneath the platysma layer.