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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Endpoint:
sensitisation data (humans)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Details about test substance composition, test method and procedures are missing. Read across from a similar substance which has the same main component and with a different counter ion that does not influence the characteristics related to the specific end-point.

Data source

Reference
Reference Type:
publication
Title:
Contact-group sensitization to triphenylmethane dyes.
Author:
Bielicky T., Novak M
Year:
1969
Bibliographic source:
Arch Derm - vol 100, Nov 1969

Materials and methods

Type of sensitisation studied:
skin
Study type:
survey
Principles of method if other than guideline:
The possibility of cross-sensitization of some triphenylmethane dyes was evaluated by patch test. Malachite Green at 2 % in water was administrated to 11 patients. The patch tests were put on for 20 to 24 hours and were evaluated for six to seven days.
GLP compliance:
no
Remarks:
pre GLP

Test material

Constituent 1
Reference substance name:
Malachite Green
IUPAC Name:
Malachite Green

Method

Type of population:
general
Subjects:
11 patients: test was executed on 9 patients, in two cases was not done
Route of administration:
dermal
Details on study design:
Patients with clinical signs of contact sensitivity to therapeutically used TPM dyes were patch tested.

TYPE OF TEST USED: patch test (epicutaneous test)

ADMINISTRATION
- Concentrations: Malachite Green at 2 % in water.
- Exposure period: from 20 to 24 hours
- Observation period: for 6 to 7 days

EXAMINATIONS
The patch tests were put on for 20 to 24 hours and they were evaluated for six to seven days. Since the skin is colored by the tested dye, it was not possible to evaluate the erythematous reaction. For this reason evaluation was recorded as follows:
Itching ±
Isolated papules +
Edema, confluent papules, infiltration + +
Vesicular reaction + + +

Results and discussion

Results of examinations:
The simultaneous positive reactions after crystal violet (contained in gentian violet), Brilliant Green, and Malachite Green in the majority of sensitive patients indicate the possibility of cross-sensitization. Malachite Green was not therapeutically used in our patients and this supports the opinion that there was no isolated sensitization to the individual dyes. It is not easy to decide which of the two remaining dyes was the primary sensitizer. If we support the contention that the reaction to the primary sensitizer is stronger, then for patients 8, 10, and 11 the brilliant green was the primary sensitizer and in patient 3 the crystal violet.

Applicant's summary and conclusion

Conclusions:
Patch test of Malachite Green resulted in same case positive and in others negative: 6 positive cases on 9 patients tested.
Executive summary:

In 11 patients with eczema localized mainly on the legs, 11 cases of sensitization were observed to brilliant green. In these cases, a simultaneous sensitivity to gentian violet (crystal violet) was found in eight and to Malachite Green in six patients. Patch tests with various triphenylmethane (TPM) dyes have shown the possibility of cross-sensitization between crystal violet (contained in gentian violet), brilliant green, and Malachite Green. The probable determinant groups of sensitization are -N(CH3)2 or -N(C2H5)2in the para position of the benzene ring structure.

Malachite Green was not therapeutically used in patients and this supports the opinion that there was no isolated sensitization to the individual dyes. It is not easy to decide which of the two remaining dyes was the primary sensitizer. If it is supported that the reaction to the primary sensitizer is stronger, for patients 8, 10, and 11 the brilliant green was the primary sensitizer and in patient 3 the crystal violet.

Conclusion

Patch test of Malachite Green resulted in same case positive and in others negative: 6 positive cases on 9 patients tested.