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Registration Dossier
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EC number: 231-143-9 | CAS number: 7440-33-7
Skin sensitisation
Administrative data
- Endpoint:
- skin sensitisation: in vivo (non-LLNA)
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 1998-03-31 to 1999-04-07
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
- Remarks:
- Well documented OECD guideline study performed under GLP.
Data source
Reference
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 1 999
- Report date:
- 1999
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 406 (Skin Sensitisation)
- GLP compliance:
- yes
- Type of study:
- guinea pig maximisation test
- Justification for non-LLNA method:
- A 1999 guinea pig sensitisation study was available of good quality. Therefore, there is no need to conduct a LLNA study as the guinea pig sensitisation study scientifically fulfills the endpoint. The OECD 406 method provides sensitisation information likely to arise from exposure to test substance via intradermical injection and/or epidermical application to guinea pigs. The guinea pig sensitisation test detects chemicals with moderate to strong sensitisation potential, as well as those with relatively weak sensitisation potential. In such methods activity is measured as a function of challenge-induced dermal hypersensitivity reactions elicited in test animals compared with controls. In addition, guinea pigs have been the animal of choice for predictive sensitisation tests for several decades (way before the LLNA became the test of choice).
The existing guinea pig data submitted here is of good quality as clear results are presented in this robust summary and test methodology followed OECD 406 guidelines, and conducted under GLP. This study it is considered acceptable according to page 266 in ECHA's Chapter r7a on Guidance on Information Requirements and Chemical Safety Assessment.
Test material
- Reference substance name:
- Tungsten
- EC Number:
- 231-143-9
- EC Name:
- Tungsten
- Cas Number:
- 7440-33-7
- Molecular formula:
- W
- IUPAC Name:
- tungsten
- Reference substance name:
- Tungsten metal
- IUPAC Name:
- Tungsten metal
- Details on test material:
- - Name of test material (as cited in study report): Tungsten Metal powder
- Physical state: Grey powder
- Analytical purity: >99%
Constituent 1
Constituent 2
In vivo test system
Test animals
- Species:
- guinea pig
- Strain:
- Dunkin-Hartley
- Sex:
- male
- Details on test animals and environmental conditions:
- TEST ANIMALS
- Source: D. Hall, Newchurch, Staffs, UK
- Age at study initiation: 4 to 7 wks
- Weight at study initiation: 371 to 436 g
- Housing: In groups of five in suspended metal cages with wire mesh floors.
- Diet: ad libitum Vitamin C enriched (Harlan Teklad 9600 FD2 SQC). Hay was given thrice weekly.
- Water: ad libitum
- Acclimation period: 5 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 16 to 25.5
- Humidity (%): 37 to 66
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light):12/12
IN-LIFE DATES: From: 1998-03-31 to: 1998-05-01
Results and discussion
In vivo (non-LLNA)
Resultsopen allclose all
- Key result
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- test chemical
- Dose level:
- 20% w/v in water
- No. with + reactions:
- 0
- Total no. in group:
- 10
- Clinical observations:
- No signs of ill health or toxicity were recorded.
- Remarks on result:
- no indication of skin sensitisation
- Remarks:
- Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. No with. + reactions: 0.0. Total no. in groups: 10.0.
- Key result
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- test chemical
- Dose level:
- 20% w/v in water
- No. with + reactions:
- 0
- Total no. in group:
- 10
- Clinical observations:
- No signs of ill health or toxicity were recorded.
- Remarks on result:
- no indication of skin sensitisation
- Remarks:
- Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No signs of ill health or toxicity were recorded..
- Key result
- Reading:
- 1st reading
- Hours after challenge:
- 24
- Group:
- negative control
- No. with + reactions:
- 0
- Total no. in group:
- 5
- Remarks on result:
- no indication of skin sensitisation
- Remarks:
- Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. No with. + reactions: 0.0. Total no. in groups: 5.0.
- Key result
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- negative control
- No. with + reactions:
- 0
- Total no. in group:
- 5
- Remarks on result:
- no indication of skin sensitisation
- Remarks:
- Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. No with. + reactions: 0.0. Total no. in groups: 5.0.
- Key result
- Reading:
- 2nd reading
- Hours after challenge:
- 48
- Group:
- positive control
- Dose level:
- 10% hexyl cinnamic aldehyde (HCA) in Alembicol D - Not concurrent
- No. with + reactions:
- 15
- Total no. in group:
- 15
- Clinical observations:
- Dryness and sloughing of the epidermis
- Remarks on result:
- positive indication of skin sensitisation
Any other information on results incl. tables
RESULTS
Dermal reactions seen following the induction:
- Intradermal injections:
Necrosis was recorded at most sites receiving Freund's Complete Adjuvant in both test and control animals.
Slight irritation was seen in most test animals at sites receiving Tungsten metal powder (20% w/v) in sterile water. No irritation was observed in control animals receiving sterile water for injection.
Topical application:
Slight erythema was observed in most test animals following topical application with Tungsten metal powder, 70% w/v in distilled water. Slight erythema was also seen in most of the control guinea-pigs after topical application of distilled water alone.
- Dermal reactions elicited by the challenge applications:
No dermal reactions were seen in any of the test or control animals.
BODYWEIGHT
Bodyweight increases were recorded for all guinea pigs over the period of the study.
CLINICAL SIGNS
No signs of ill health or toxicity were recorded.
Applicant's summary and conclusion
- Interpretation of results:
- GHS criteria not met
- Conclusions:
- Under conditions of this study, Tungsten metal powder did not produce evidence of skin sensitisation (delayed contact hypersensitivity).
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