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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
12 October 1995-26 October 1995
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference Type:
study report

Materials and methods

Test guideline
according to guideline
OECD Guideline 402 (Acute Dermal Toxicity)
GLP compliance:
yes (incl. QA statement)
Test type:
fixed dose procedure
Limit test:

Test material

Constituent 1
Chemical structure
Reference substance name:
EC Number:
EC Name:
Cas Number:
Molecular formula:
disodium 4-amino-6-{2-[4-({4-[2-(2,4-diaminophenyl)diazen-1-yl]phenyl}sulfamoyl)phenyl]diazen-1-yl}-5-hydroxy-3-[2-(4-nitrophenyl)diazen-1-yl]naphthalene-2,7-disulfonate

Test animals

other: Alpk: APfSD (Wistar)
Details on test animals or test system and environmental conditions:
Species: Rat
strain: Alpk: APfSD (Wistar)
source: Barriered Animal Breeding Unit, zeneca Pharmaceuticals, Alderley Park
Sex: female and male
specification: young adults. Males weighed 247-273g and the females weighed 178-210g at the beginning of the study

The rats were housed individually, in multiple rat racks suitable for animlas of this strain and the weight range expected during the course of the study.
The rats were transferred to clean cages and racks, as necessary, during the study.
The animal room was designed to give the environmental conditions shown below:
temperature: 21±2°C
relative humidity: 40-70%
Air: approximately 25-30 changes/hour
light cycle: artificial giving 12 hours light, 12 hours dark.

Both temperature and relative humidity were monitored continuosly using an automated system which triggers an alarm if values are outside specified ranges. In general, the recorded values were within the specified ranges and any deviations that were observed are considered not to have affected the integrity of the study.
Diet (PCD) supplied by Special diet Services Limited, Witham, Essex, UK and mains water, supplied by an automatic system were available ad libitum.
Each batch of diet is routinely analysed for composition and for presence of contaminants. Water is also periodically analysed for the presence of contaminants. No contaminants were found to be present in the diet or water at levels considered to be capable of interfering with the purpose or outcome of the study.

The animals were housed under the experimental conditions for at least 6 days, prior to the start of the study.

Five male and five female rats were allocated to the study. Animals were individually identified with a number, unique within the study, by ear punching.
On the front of each cage of animals was a card identifying the contained animals by procedure code, test substance, date of dministration, dose level, individual number, sex and study.

Administration / exposure

Type of coverage:
other: deionised water
Duration of exposure:
24 h
single limit dose level of 2000 mg/kg
No. of animals per sex per dose:
5 males and 5 females
Control animals:
Details on study design:
As no deaths were noted in the speculative study, a single, limit dose level of 2000 mg/kg was administered.
The appropriate amount of the test sample was weighed onto a plastic weighing boat and made into a paste by adding a small amount (0.5-0-6ml) of deionised water. The amount applied was calculated for each animal according to its weight at the time of dosing. The test sample covered approximately two-thirds of the application site and the estimated amount applied per unit area of skin was 14.8-16.4mg/cm2 for males and 10.7-12-6mg/cm2 for females. The paste, covered by a 4 ply gauze patch (approximately 7cmx7cm) was applied to the shorn back of each animals and was kept in contact for 24 hours using an occlusive dressing. The gauze patch was covered by a patch of plastic film (7cmx7cm) and was held in position using adhesive bandage (25cmx7.5cm) which was secured by two pieced of PVC tape (approximately 2.5cmx20cm).

At the end of the 24-hour contact period, the dressing were carefully cut, using blunt tipped scissors, removed and discarded. the skin, at the site of application, was cleansed free of any residual test sample using clean swabs of absorbent cotton wool soaked in clean warm water and was then dried with clean tissue paper.

Results and discussion

Effect levels
Key result
Dose descriptor:
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
none of the animals died
Clinical signs:
other: no sign of toxicity. The skin of all the animlas was stained black or purple by the test sample and in some animals the application site was obscured, preventing the full assessment of irritation. there were pratically no signs of skin irritation (one mal
Other findings:
Apart from staining of the hair/skin by the test sample, there were no abnormalities in any animal.

Applicant's summary and conclusion

Interpretation of results:
other: not irritant
LD50 > 2000 mg/kg to male and female rats.
Executive summary:

A group of five male and five female Alpk: APfSD (Wistar) rats received a single dermal application of substance.

The animals were assessed daily for the following 14 days for any signs of systemic toxicity and their bodyweights were recorded at intervals throughout the study. At the end of the study all the animals were killed and subjected to a macroscopic examination post mortem.

Following a single dermal application of  2000 mg/kg, none of the animals died. There were no signs of  toxicity and practically no signs of skin irritation.