Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Toxicological information

Skin sensitisation

Currently viewing:

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1993-03-31 to 1996-01-23
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Suitable non-LLNA data was already available. Therefore the generation of new LLNA data is not necessary.

Test material

Constituent 1
Chemical structure
Reference substance name:
Disodium molybdate
EC Number:
231-551-7
EC Name:
Disodium molybdate
Cas Number:
7631-95-0
Molecular formula:
MoO4.2Na
IUPAC Name:
Disodium tetraoxomolybdate
Specific details on test material used for the study:
- Name of test material (as cited in study report): Sodium molybdate 241/32
- Physical state: white powder
- Analytical purity: 40.52% molybdenum, 19.29% sodium
- Purity test date: 1993-05-13
- Batch No.: 241/32
- Storage condition of test material: room temperature

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: D. Hall, Newchurch, Staffordshire, England
- Age at study initiation: 6 to 7 weeks
- Weight at study initiation: 286 to 377 g
- Housing: in groups of 10 in suspended metal cages with wire mesh floors
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 °C
- Humidity (%): 30 to 70 %
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal
Vehicle:
water
Concentration / amount:
5 % (w/w) / 0.1 mL
Route:
intradermal
Vehicle:
other: Freund´s complete adjuvant
Concentration / amount:
50/50 mixture of Freund`s complete adjuvant and water for irrigation
Route:
intradermal
Vehicle:
water
Concentration / amount:
5% (w/w) in a 50/50 mixture of Freund´s complete adjuvant and water for irrigation
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
70% (w/w)
Adequacy of induction:
non-irritant substance, but skin pre-treated with 10% SDS
Challengeopen allclose all
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
70% (w/w) applied to the anterior site
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
water
Concentration / amount:
35% (w/w) applied to the posterior site
No. of animals per dose:
20
Details on study design:
RANGE FINDING TESTS:
- 2 guinea-pigs
- Intradermal injection: 0.1, 0.25, 0.5, 1.0, 2.5, 5.0, 7.5 and 10.0 % w/w sodium molybdate 241/32 in water and vehicle control
- Epicutaneous application: 30, 50, 60 and 70 % w/w sodium molybdate 241/32 in water

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 1x intradermal, 1x epicutaneous
- Exposure period: 48 h of occlusive topical application
- Test groups: 1
- Control group: 2
- Site: 40 x 60 mm area of dorsal skin on the scapular region

Control and test animals were challenged topically two weeks after the topical induction

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Exposure period: 24 h
- Test groups: 1
- Control group: 1
- Site: 20 x 20 mm patch applied to both anterior and posterior flank sides
- Concentrations: saturated Whatman No. 3 paper with 0.2 ml of Sodium molybdate 241/32 either 70 % (anterior) or 35 % (posterior) w/w in water
- Evaluation (hr after challenge): 24, 48 and 72 hours after removal of the patches

OTHER:
The preliminary investigations indicated, that topical application of 70 % w/w sodium molybdate 241/32 in water did not cause skin irritation. Therefore, six days after the intradermal injections, the same 40 x 60 mm area was clipped and shaved free of hair and the site was pre-treated by gentle rubbing with 0.2 mL per site of 10 % w/w sodium lauryl sulphate in petrolatum. 24 hours later a 20 x40 mm patch of Whatman No. 3 paper was saturated with 0.4 mL of Sodium molybdate 241/32, 70% w/w in distilled water. The patch was placed on the skin under occlusive conditions and left in place for 48 hours.
Challenge controls:
Animals that were treated the same way like test animal for the procedure of induction with the exception that the sodium molylbdate 241/32 was omitted. The challenge procedure was likewise to the test animals.
Positive control substance(s):
yes
Remarks:
formalin

Results and discussion

Positive control results:
Sensitivity of the guinea-pig strain used is checked periodically with formalin, a known sensitiser. Formalin produced a clear positive response in all performed control experiments.

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
70 and 35 % Sodium molybdate 241/32 w/w in water
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
70 and 35 % of Sodium molybdate 241/32 w/w in water
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Key result
Reading:
other: 3rd reading
Hours after challenge:
72
Group:
test chemical
Dose level:
70 and 35 % Sodium molybdate 241/32 w/w in water
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
Freud's treated control
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
no indication of skin sensitisation
Reading:
other:
Group:
positive control
Dose level:
Formalin (Induction: Intradermal 0.1% , topical 10 % aqueous dilution)
No. with + reactions:
10
Total no. in group:
10
Remarks on result:
positive indication of skin sensitisation

Any other information on results incl. tables

Clinical signs:

No signs of toxicity were recorded.

Induction:

- Intradermal injections: Necrosis was recorded at sites receiving Freund´s Complete Adjuvant in test and control animals. A slight irritation was seen in test animals at sites receiving Sodium molybdate, 5% w/w in water for irrigation; no irritation was observed in the control animals receiving water for irrigation.

- Topical application: Slight erythema was observed in test animals following topical application with Sodium molybdate 241/32, 70% w/w in distilled water. Very slight erythema was seen in the control guinea-pigs.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
In conclusion, Sodium molybdate 241/32 is considered as not skin sensitising.
Executive summary:

In a dermal sensitization study (OECD 406) with Sodium molybdate in water, 20 young adult female guinea-pigs of the Dunkin-Hartley strain were tested using the method of Magnusson and Kligman. No dermal reactions were seen in a period of 72 hours after challenging the test animals. In this study, Sodium molybdate is not a dermal sensitizer.