Hydrogen fluoride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14.11.1989 - 05.12.1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

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:

Flußsäure 5% (hydrofluoric acid). Manufactured by Bayer AG, batch no. E 7931, a colourless liquid. Composition 5.1% HF in water, pH 1.8. Stability guaranteed for the study period, stored at room temperature in darkness.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Healthy adult albino rabbits, strain HC:NZW. Obtained fom Interfauna UK Ltd, Huntingdon. The state of health of the animals was routinely examined for the main specific pathogens. Females were nulliparous and nonpregnant. Vaccination or antibiotic treatment was not carried at any time prior to receipt or during acclimatisation or the study itself. Rabbits were examined one day prior to the start of the study to establish that they were biologically normal. Only animals which did not exhibit any alterations of the skin were used. In the interests of animal welfare, rabbits from former studies that tolerated treatment without signs were also used. The skin area that served as a control in the preceeding study was use at the test site in the following study. If animals were re-used they underwent a treatment-free period prior to commencment of the second study.

The rabbits were housed individually under standardised conventional conditions in stainless steel cages. The temperature was maintained at 20±3°C, and relative humidity approx. 50%. Light was provided on a 12 hour light-dark cycle at approx. 27 Watt/m² floor area. There were approx. 10 air changes per hour.Rabbits were identified by individual ear tattoos and cage cards. The acclimatisation period was at least 14 days (collective faeces specimens were examined for Coccidia oocysts during this period). Rabbits were fed a standard diet (Ssniff K4) once daily in the morning, each animal received approx. 100-120 g per day. Tap water was available for ad libitum consumption (in polycarbonate bottles, or between 7 and 19 hours from automatic watering apparatus).

The rabbits were weighed immediately prior to test substance application.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

water

Controls:

yes, concurrent vehicle

Amount / concentration applied:

500 µl of test substance was applied to the patch. The control patch was moistened with water.

Duration of treatment / exposure:

4 hours

Observation period:

14 days

Number of animals:

3 female rabbits

Details on study design:

Rabbits were randomly assigned to treatment groups. Approximately 24 hours before the test, fur was removed by clipping (electric clippers) from the dorso-lateral area of the trunk (6x6 cm). A hypoallergenic patch soaked in test substance was applied to the shaved area. A patch moistened with water was placed on the opposite side of the animal to serve as a control. The patches were loosely held in place by means of a semiocclusive dressing. After the exposure period the dressing and patches were removed, and the exposed skin areas were carefully washed with water.
Draize scores for erythema/eschar formation and oedema formation were evaluated separately, giving an individual irritation index per animal. Assessments were made 1 hour after removal of the patches, then at 24 h, 48 h, 72 h, 7 d and 14 d later.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: mean across all 6 time points

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 d

Remarks on result:

other: Mean erythema score from 6 timepoints (1, 24, 48, & 72 hrs & 7 & 14 days)

Results 2

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: mean across all 6 time points

Score:

1

Max. score:

1

Remarks on result:

other: Mean edema score from 6 timepoints (1, 24, 48, & 72 hrs & 7 & 14 days)

Results 3

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: mean across all 6 time points

Score:

1

Max. score:

2

Remarks on result:

other: Mean erythema score from 6 timepoints (1, 24, 48, & 72 hrs & 7 & 14 days)

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: mean across all 6 time points

Score:

0.3

Max. score:

2

Remarks on result:

other: Mean edema score from 6 timepoints (1, 24, 48, & 72 hrs & 7 & 14 days)

Results 5

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

other: mean across all 6 time points

Score:

4

Max. score:

4

Reversibility:

not fully reversible within: 14 d

Remarks on result:

other: Mean erythema score from 6 timepoints (1, 24, 48, & 72 hrs & 7 & 14 days)

Results 6

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: mean across all 6 time points

Score:

1.3

Max. score:

4

Remarks on result:

other: Mean edema score from 6 timepoints (1, 24, 48, & 72 hrs & 7 & 14 days)

Irritant / corrosive response data:

Marked eschar formation with destruction of underlying tissue was observed at the exposed site in two animals after 24 hours, up to day 14.

Other effects:

No other effects were observed

Any other information on results incl. tables

Draize scores assigned to 3 female rabbits following 4 hours semiocclusive application of 5% HF to the skin.

 

		DRAIZE grade after												Irritation Index
Animal	Body Weight	1 h		24 h		48 h		72 h		7 d		14 d
		e	o	e	o	e	o	e	o	e	o	e	o	e	o
Y30	3.7 kg	1	1	4	1	4	1	4	1	4	1	4	0	4.0	1.0
Y27	2.5 kg	2	2	1	1	1	0	1	0	0	0	0	0	1.0	0.3
Y32	3.3 kg	2	2	4	2	4	1	4	1	4	3	4	4	4.0	1.3

e = erythema and eshcar formation

o = oedema formation

Applicant's summary and conclusion

Interpretation of results:

corrosive

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on the results obtained 5% hydrofluoric acid was regarded as corrosive.

Executive summary:

The irritant/corrosive potential of 'Flußsäure 5%' (hydrofluoric acid) to the skin of 3 female rabbits was determined in accordance with OECD guideline 404. A patch soaked with the test substance was applied to the skin under a semiocclusive dressing for 4 hours. The resultant erythema/eschar formation and oedema formation was assessed according the Draize scoring system. The results were interpreted according to the OECD guide. Marked eschar formation with tissue destruction was observed which did not prove to be reversible within 14 days. Based on these results, 5% hydrofluoric acid can be classified as corrosive.