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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1986-10-06 to 1987-01-10
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Meets generally accepted scientific standards, well documented and acceptable for assessment. Combined study therefore restriction based on some details lacking.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1987
Report Date:
1987

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
Freund's complete adjuvant test
Justification for non-LLNA method:
The substance and a related analigue substance are considered to have surfactant properties and so the choice of test method was determined on this basis, also the study was conducted 20+ years ago and this was before the standard LLNA approach was introduced.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): [CAS Number 171171-80-5]
- Physical state: Dark brown viscous liquid
- Lot/batch No.: XSA 053J
- Storage condition of test material: In the dark at ambient temperature
- Stability under test conditions: Infra-red spectra taken on 14 August 1986 and 18 December 1986 showed no differences and the substance was judged to have been stable for the duration of the study

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Porcellus Ltd, UK
- Weight at study initiation: 551-639 g (males) and 494-581 g (females)
- Housing: Guinea pigs were randomised into single sex groups of 10 animals and, following the acclimation period, were housed in groups of 5 animals (two and three per cage). Hanging stainless steel cages with all-mesh floors and tops and half-mesh fronts were used, mounted in four rows of three on a single-sided rack (a total of 12 cages); each cage measured 54 cm x 31 cm x 36 cm. Sawdust filled trays for excreta were placed beneath each cage and changed thrice weekly.
- Diet: SGI with vitamin C supplement (Grain Harvesters Ltd, Kent) ad libitum by means of a top loading food hopper
- Water: Filtered but untreated water from the public supply ad libitum by means of an automatic valve-regulated drinking line
- Acclimation period: = 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature: 19-23 degrees Centigrade
- Photoperiod: Automatically controlled cycle of light (06:00 to 18:00) and dark (18:00 to 06:00)

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
corn oil
Concentration / amount:
Intradermal induction - 0.1 % (m/v) in corn oil
Topical induction - (75 % (m/v) in corn oil
Topical challenge - 50 % (m/v) in corn oil
Challengeopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
corn oil
Concentration / amount:
Intradermal induction - 0.1 % (m/v) in corn oil
Topical induction - (75 % (m/v) in corn oil
Topical challenge - 50 % (m/v) in corn oil
No. of animals per dose:
Range finding study - two males and two females (intradermal induction)
Range finding study - four males and four females (topical induction)
Main study - ten males and ten females (plus five males and five females as controls)
Details on study design:
Each animal was identified by means of a coloured body dye. The test was accomplished in two stages: range finding studies and the test itself.

RANGE FINDING

Each animal was closely shorn in the shoulder region using electric clippers followed by an electric razor and 0.1 mL of several dilutions (0.05, 0.1, 0.5 and 1.0 % [m/v] in corn oil) of the test material injected intradermally each side of the midline. The animals were examined to determine the maximum concentration that could be used without causing untoward toxicity.

Two further groups of two males and two females were taken. The flanks of each animal were closely shorn and 0.3 mL of a 50 % or 75 % [m/v] dilution of test material in corn oil was applied to 4 cm x 4cm Whatman Number 3 filter paper patches. The patches were placed on the flanks and held in place with a "Sleek" adhesive tape patch, then covered with an 8 cm "Poroplast" elastic adhesive bandage for 24 h; after this time they were removed and the animals examined for signs of irritation which was scored using a four point scale (0, 1, 2, 3). The concentration used for topical induction was that which caused irritation (1) and the concentration used for topical challenge was that which was just non-irritant (0).

MAIN TEST

The main test was divided into two stages: (a) induction by intradermal injection and topical application and (b) topical challenge.

The animals were closely shorn in the shoulder region using electric clippers followed by an electric razor; two rows of three injections were made, one on each side of the midline as follows:

Test animals
Two injections (0.1 mL) of Freund's complete adjuvant (FCA)
Two injections (0.1 mL) of the test material in solvent (corn oil)
Two injections (0.1 mL) of the test material in 50:50 FCA/solvent

Control animals
Two injections (0.1 mL) of Freund's complete adjuvant (FCA)
Two injections (0.1 mL) of solvent (corn oil)
Two injections (0.1 mL) of 50:50 FCA/solvent

One week after induction by the intradermal injections, the same area of skin was shaved using electric clippers only. A 4 cm x 4 cm patch of Whatman Number 3 filter paper was moistened with 0.3 mL of the test material, placed over the site of the injection and covered with a "Sleek" dressing. The dressing was then securely covered with an 8 cm "Poroplast" elastic adhesive bandage for 48 h. Similar patches of filter paper (but moistened with solvent only) were applied to the controls.

CHALLENGE PROCEDURE
Topical challenge was carried out two weeks after the topical induction. Hair was removed from a 3 cm x 3 cm area of one flank by clipping then shaving. A 2 cm x 2 cm patch of Whatman Number 3 filter paper, moistened with 0.1 mL of the appropriately diluted test material, was placed over the shaved area and covered with a 3 cm square of adhesive tape ("Blenderm"), held in place by an 8 cm "Poroplast" elastic bandage. Controls were also treated with the diluted test material. After 24 h, the patch was removed and the site examined for a response immediately, 24 and 48 h after its removal. The response was scored using a standard four point scale:

0: no difference from surrounding skin
1: slight redness, edges not defined
2: Pink/red square with defined edges
3: Beet red square with well defined edges

The result of the test was expressed as the numbers of positive responses (1, 2 and 3) shown by test animals at both 24 and 48 h after removal of the challenge patches. The frequency of positive responses, rather than their intensity, was regarded as the important statistic.
Positive control substance(s):
no

Study design: in vivo (LLNA)

Vehicle:
not specified
Concentration:
No data
No. of animals per dose:
No data
Details on study design:
No data
Positive control substance(s):
not specified
Statistics:
No data

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
0
Group:
test group
Dose level:
50 % test material in corn oil
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 0.0. Group: test group. Dose level: 50 % test material in corn oil. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
24
Group:
test group
Dose level:
50 % test material in corn oil
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50 % test material in corn oil. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
other: 3rd reading
Hours after challenge:
48
Group:
test group
Dose level:
50 % test material in corn oil
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading:
Reading:
1st reading
Hours after challenge:
0
Group:
negative control
Dose level:
corn oil only
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 0.0. Group: negative control. Dose level: corn oil only. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
24
Group:
negative control
Dose level:
corn oil only
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 24.0. Group: negative control. Dose level: corn oil only. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
other: 3rd reading
Hours after challenge:
48
Group:
negative control
Dose level:
corn oil only
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading:

Any other information on results incl. tables

The results of range finding studies are summarised in Table 5 (attached) and the skin reaction in guinea pigs following topical challenge is described in Table 6 (attached).

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
None of the twenty test animals showed any positive response at either 24 or 48 hours after removal of the challenge patches and it is concluded that the test material is not a skin sensitiser in guinea pigs.