Boehmite (Al(OH)O)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

25 August 2009 - 28 August 2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

: lack of detail on test substance purity; powder was not moistened

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Aluminium hydroxide / SH-20 Muster

IUPAC Name:

Aluminium hydroxide / SH-20 Muster

Constituent 2

Reference substance name:

Aluminium hydroxide

EC Number:

244-492-7

EC Name:

Aluminium hydroxide

Cas Number:

21645-51-2

Molecular formula:

AlH3O3

IUPAC Name:

aluminum trihydroxide

Details on test material:

Name: Aluminium hydroxide/SH-20 Muster
Batch No.: 40/2009
CAS No.: 21645-51-2
Appearance: Powder/white or light grey
Al hydroxide content: not reported.
Purity: “suitable chemical purity”
Storage conditions: Room temperature (15-25 °C)
Manufacture date: 19 March 2009-11-04
Expiry date: Unlimited
Safety precautions: Routine safety precautions (gloves, goggles, face mask, lab coat)
Source: Aluminium Oxid Stade GmbH
pH of the test item- 5.0

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Source: S&K-LAP Kft., 2173 Kartal, Császár út 135, HUNGARY
Age at study initiation: 10 weeks old
Body weight range at the beginning of the study: 3328-3698 g.
Body weight range at the end of study: 3507-3820 g.
Data of receipt: 29 July 2009
Acclimation: 27 days

Identification: The animals were identified by engraved ear tags. The cages were marked with individual identity cards with information about study code, sex, cage number, dose group and individual animal number.


ENVIRONMENTAL CONDITIONS

Lighting period: 12/12 cycle
Temperature:19.2± 22.7 oC
Relative humidity: 41-69%
Housing/Enrichment: Rabbits were individually housed in AAALC approved metal wire rabbit cages (65x65 cm with height of 45 cm, on 2 levels with a shelf to allow rabbits to climb up to stretch out). Cages were of an open wire structure and cages were placed together to allow some social interaction with rabbit(s) in adjoining cages.
Ventilation: 15-20 air exchange/hour

The environmental parameters were recorded twice daily during the acclimatisation and experimental phases.

Feeding conditions
Diet: The diet PURINA Base _ Lap gr . diet for rabbits produced by AGRIBRANDS Europe Hungary PLC, H-5300 Karcag, Madarasi út, Hungary, ad libitum.
The contents of PURINA Base – Lap gr. diet for rabbits provided.

Water: The animals received municipal tap water, as for human consumption, ad libitum, from an automatic system.
The drinking water is routinely analysed and is considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study. The quality control analysis is performed once every three months and microbiological assessment is performed monthly by Veszprém County Institute of State Public Health and Medical Officer Service (ÁNTSZ, H-8201 Veszprém, József A.u.36., Hungary).

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: The untreated skin of each animal served as a control.

Amount / concentration applied:

0.5 g of aluminium hydroxide applied to the test area (without vehicle).

Duration of treatment / exposure:

4 hours

Observation period:

Animals examined for erythema and oedema at 1, 24, 48 and 72 hours after patch removal.

Number of animals:

3 males per group

Details on study design:

TEST SITE
- Area of exposure: the test item was applied to an approximately 6 cm² area of intact skin
- Type of wrap if used: 3 layers of gauze

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the test item was removed after the treatment period with water at body temperature.

SCORING SYSTEM:
The dermal irritation scores were evaluated according to the scoring system by Draize (1959) (see below).

Scoring system of erythema and oedema formation

Erythema and eschar formation
No erythema 0
Very slight erythema (barely perceptible) 1
Well defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) to slight eschar
formation (injuries in depth) 4

Maximum possible erythema score: 4

Oedema formation
No oedema 0
Very slight oedema (barely perceptible) 1
Slight oedema (edges of it will be well defined
by definite raising) 2
Moderate oedema (raised appr. 1 mm) 3
Severe oedema (raised more than 1 mm and extending
beyond area of exp.) 4

Maximum possible oedema score: 4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: no effects

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: no effects

Irritant / corrosive response data:

At observation one hour after patch removal, very slight erythema (score 1) was observed in two animals.

At 24, 48 and 72 hours after patch removal, there were no observed clinical signs noted on the skin of the treated animals.

As no clinical signs were observed up to 72 hours after patch removal, the study was terminated after the 72 hour observation.

Other effects:

Mortality
There was no mortality observed during the study.

Body weight
There was no effect of treatment on body weight.

Clinical observation/General Daily Examination
There were no treatment-related clinical signs noted.

Any other information on results incl. tables

TABLE 1. SCORING OF ERYTHEMA FORMATION

Animal No./ Sex	Body weight (g)		1 h	24 h	48 h	72 h
	at the beginning of the study	at the end of the study
00331/ M	3697	3820	1	0	0	0
00983/ M	3328	3507	1	0	0	0
00892/ M	3540	3603	0	0	0	0
TOTAL	-	-	2	0	0	0

 

TABLE 2. SCORING OF OEDEMA FORMATION

Animal No./ Sex	Body weight (g)		1 h	24 h	48 h	72 h
	at the beginning of the study	at the end of the study
00331/ M	3697	3820	0	0	0	0
00983/ M	3328	3507	0	0	0	0
00892/ M	3540	3603	0	0	0	0
TOTAL	-	-	0	0	0	0

M       = male

d        = day

h        = hour

 

TABLE 3. MEAN VALUES OF SKIN IRRITATION SCORES

(24, 48, 72 hours reading)

Animal Number	Sex	Erythema	Oedema
00331	male	0.00	0.00
00983	male	0.00	0.00
00892	male	0.00	0.00

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information According to the scoring criteria in OECD 404 test (Acute dermal irritation/corrosion) conducted, Al hydroxide is not a skin irritant/corrosion agent on acute dermal skin contact. Criteria used for interpretation of results: EU

Conclusions:

General toxicity
No clinical signs of general toxicity, mortality and effects on body weight gain were observed in laboratory animals after an acute dermal contact with Al hydroxide (powder).

Irritation effects
No skin irritation/ corrosion effects were reported - no erythema/eschar or oedema were observed in exposed animals 24, 48 and 72 hours after exposure.

Executive summary:

The test item was administered as supplied, at a single dose of. Gauze was placed onto the hairless skin of the rabbit, test item was applied to the gauze, additional gauze was placed over the test item and an adhesive clear plastic patch applied. The trunk was wrapped in clear plastic with medical tubing used to hold the patch in place. The untreated skin of each animal served as control.

 

After 4 hours, the remaining test item was removed with water at body temperature.

 

To assess skin irritation, animals were examined at 1, 24, 48 and 72 hours after the patch removal. Additional general examinations were performed daily.

 

There was no mortality or systemic clinical changes related to Aluminium Hydroxide administration.

 

There was no effect of treatment on body weight.

 

At observation one hour after patch removal, very slight erythema (score 1) was observed in two animals.

 

At 24, 48 and 72 hours after patch removal, there were no observed clinical signs noted on the skin of the treated animals.

 

As no clinical signs were observed up to 72 hours after patch removal, the study was terminated after the 72 hour observation.

 

The animals’ individual means scores (considering readings at 24, 48 and 72 hours after patch removal) for erythema and oedema were 0.00, 0.00 and 0.00 respectively.

.