Registration Dossier

Administrative data

Description of key information

No skin sensitization effects were observed in test group or control group. Therefore, the test chemical was considered to be not sensitizing to human skin.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
Data is from publication.
Qualifier:
according to
Guideline:
other: As mention below
Principles of method if other than guideline:
Patch test wawsperfromed to evaluate the sensitization potential of the test chemical among workers working in a furniture factory
GLP compliance:
not specified
Type of study:
patch test
Justification for non-LLNA method:
Not specified.
Species:
other: Human
Strain:
other:
Remarks:
Not applicable
Sex:
not specified
Details on test animals and environmental conditions:
Details on test animal
TEST ANIMALS
72 furniture factory workers were investigated with the history of allergic contact eczema caused by true teak (Tectona grandis). All the 72 workers were interviewed and examined for skin lesions.
Route:
epicutaneous, occlusive
Vehicle:
not specified
Concentration / amount:
Native teak dust was applied which contain unknown concentration of 2-methyl-9,10-anthraquinone.
Day(s)/duration:
24 hour
Adequacy of induction:
not specified
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
other: Acetone
Concentration / amount:
0.1,0.5, 1 and 2%
Day(s)/duration:
24 hour
Adequacy of challenge:
not specified
No. of animals per dose:
72 Human volunteers
Details on study design:
Details on study design

MAIN STUDY

A. INDUCTION EXPOSURE
- No. of exposures: single
1- Exposure period: 24 hour
- Test groups: 72
- Control group:10
- Site: The patch was applied on the volar side of the left forearm.
- Frequency of applications: No data available.
- Duration: 24 hour
- Concentrations: native teak dust was applied which contain unknown concentration of the test chemical

B. CHALLENGE EXPOSURE
- No. of exposures:4
- Day(s) of challenge: No data available.
- Exposure period: 24 hour
- Test groups:72
- Control group:10
- Site: The patch was applied on the volar side of the left forearm.
- Concentrations: 0.1,0.5, 1 and 2%
- Evaluation (hr after challenge):24 ,48 and 72 hour


Other:The interpretation of the patch testswas based on the usual criteria and was recorded as allergic, toxic, or negative.
Challenge controls:
Yes, 10 challenge controls were investigated
Positive control substance(s):
not specified
Positive control results:
No data available.
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
0.1,0.5, 1 and 2%
No. with + reactions:
0
Total no. in group:
72
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
0.1,0.5, 1 and 2%
No. with + reactions:
0
Total no. in group:
72
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
72
Group:
test group
Dose level:
0.1,0.5, 1 and 2%
No. with + reactions:
0
Total no. in group:
72
Clinical observations:
No skin sensitization effect were observed.
Remarks on result:
no indication of skin sensitisation
Interpretation of results:
other: not sensitizing
Conclusions:
No skin sensitization effects were observed in test group or control group. Therefore, the test chemical was considered to be not sensitizing to human skin.
Executive summary:

Patch test was performed to evaluate the sensitization potential of the test chemical among workers working in a furniture factory

A group of 72 furniture factory workers were investigated with the history of allergic contact eczema caused by true teak (Tectona grandis). All the 72 workers were interviewed and examined for skin lesions. For this purpose a Patch test was performed with native teak dust. The patch were applied for 24 hours on the volar side of the left forearm and read at the end of this period and read again after 48 and 72 hours. A challenge exposure was performed on the workers who showed allergic reactions. The patch was applied at the concentration of 0.1, 0.5, 1 and 2% test chemical. Acetone was used as vehicle.The interpretation of the patch tests was based on the usual criteria and was recorded as allergic, toxic, or negative.Identical Patch tests were applied on 10 controls. No skin sensitization effects were observed in test group or control group. Therefore, the test chemical was considered to be not sensitizing to human skin.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Various studies have been reviewed to determine the allergic potential of the test chemical in living organisms. These include in vivo experimental studies in humans as well as estimated data for the test chemical. The results are summarized as follows:

Patch test was performed to evaluate the sensitization potential of the test chemical among workers working in a furniture factory

A group of 72 furniture factory workers were investigated with the history of allergic contact eczema caused by true teak (Tectona grandis). All the 72 workers were interviewed and examined for skin lesions. For this purpose a Patch test was performed with native teak dust. The patch were applied for 24 hours on the volar side of the left forearm and read at the end of this period and read again after 48 and 72 hours. A challenge exposure was performed on the workers who showed allergic reactions. The patch was applied at the concentration of 0.1, 0.5, 1 and 2% test chemical. Acetone was used as vehicle.The interpretation of the patch tests was based on the usual criteria and was recorded as allergic, toxic, or negative.Identical Patch tests were applied on 10 controls. No skin sensitization effects were observed in test group or control group. Therefore, the test chemical was considered to be not sensitizing to human skin.

Skin sensitization effects were also estimated by three different models i.e, Battery, Leadscope and SciQSAR used within Danish QSAR database for the test chemical

Based on estimation, no skin sensitization reactions were observed in guinea pigs and humans. Therefore, the test chemical was considered to be not sensitizing.

The estimated result is further supported by a series of Patch tests performed with native teak dust moistened with water were applied on 10 "controls" and 112 workers who were exposed to teak in various working procedures. Moistened teak dust produced toxic reactions in 20.5 %, while native teak dust did not have primary irritant effects and was, therefore, considered to be the substance of choice for patch testing.

Patch tests were applied both with fresh native teak dust and dust moistened with water. The patch tests were carried out in the usual way and applied on the volar side of the left forearm. The patches were applied for 24 hours and read at the end of this period and read again after 48 and 72 hours. The interpretation of the patch tests was based on the usual criteria, and was recorded as allergic, toxic, or negative.

Patch testing was performed using the same technique on 10 nurses used as "controls". The testing was repeated after four weeks using teak dust which had been kept unsealed.

The patch tests with native teak dust were all negative at the first application. An allergic reaction was recorded in two cases when retested. Using moistened teak dust, toxic reactions were registered in seven cases, and four of these were of the bullous type. On repetition four weeks later, the toxic reactions had diminished, and in three cases they had disappeared. No bullous reaction was recorded.

18.7% of the workers showed an allergic skin reaction to native teak dust. The diagnosis of allergic contact eczema was made in 12. 5% and 6.2% were considered to have latent allergy. Primary irritant (contact) eczema was considered to be present in four individuals who had experienced acute, transitory, eczematous eruptions during the hot part of the summer when they perspired freely.

Since, positive reactions were observed in only 18-21 workers of the 112 tested, the test chemical can be considered to be not sensitizing to skin.

Based on the available results, the test chemical can be considered to lack the potential to cause dermal sensitization. Hence, the test chemical can be considered to be not sensitizing to skin.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on the available results, the test chemical can be considered to lack the potential to cause dermal sensitization. Hence, the test chemical can be considered to be not sensitizing to skin.