Methanaminium, N-[4-[[4-(dimethylamino)phenyl]phenylmethylene]-2,5-cyclohexadien-1-ylidene]-N-methyl-, ethanedioate

Endpoint summary

Description of key information

Not skin irritating

Eye Dam. 1, H318

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The experiment is scientifically acceptable, nevertheless details about test method and procedures are missing.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

1981

GLP compliance:

not specified

Species:

rabbit

Strain:

other: CPH

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: from Statens Sevlmlnstimt, (Copenhagen, Denmark).
- Weight at study initiation: 2.7 kg.

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Concentration: 100 µl.
- Application: aqueous solution (76 mg/kg) was deposited in the lower conjunctival sack of the left eye.

Observation period (in vivo):

8 days

Number of animals or in vitro replicates:

Three rabbits + one

Details on study design:

Three rabbits were treated with 8 % aqueous solution; a further single rabbit was treated with fine crystals (particle size 60-90 µm).

TOOL USED TO ASSESS SCORE: examinatious carried out with an ophthalmoscope and 1 % sodium fluorescein solution.

Remarks on result:

other: results are reported in the other sections

Irritant / corrosive response data:

Instillation of 8 % aqueous solution produced marked edema, substantial discharge and slight hyperemia of the conjunctiva which disappeared after 24 h in two out of three rabbits. No effect on cornea or iris was observed and all were fully restituted after 8 days.
The rabbit treated with fine crystals showed a totally opaque cornea and bright red and edemateous conjunctivae which remained for a forthnight.

.

Interpretation of results:

other: Eye Dam. 1 (H318), according to the CLP Regulation (EC 1272/2008)

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Eye Dam. 1, H318

Executive summary:

100 µl of Malachite Green Oxalate was deposited in the lower conjunctival sack of the left eye while the fight eye served as a control. Treatment and observations were in accordance with the OECD guidelines (1981), and examlnatious carried out with an ophthalmoscope and 1 % sodium fluorescein solution. Instillation of 8 % aqueous solution produced marked edema, substantial discharge and slight hyperemia of the conjunctiva which disappeared after 24 h in two out of three rabbits. No effect on cornea or iris was observed and all were fully restituted after 8 days.

A single rabbit was treated with fine crystals (particle size 60-90 µm) which produced a totally opaque cornea and bright red and edemateous conjunctivae which remained for a forthnight.

Conclusion

An harmonized classification and labelling (C&L) has already been approved for Malachite Green chloride (EC: 209-322-8) and oxalate (EC: 219-441-7) salts. The classifications have been discussed by Commission of the European Communities and the related information was presented in ECBI/54/02 report, 18th July, 2002 (Health and Safety Executive, UK. 2005). In this context, the current study outcomes have been reviewed and the effects occurring in the rabbit treated with fine crystals were judged as sufficient to support the current classification: Xi; R41 (corresponding to Eye Dam. 1, H318 of the CLP Regulation (EC 1272/2008).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

SKIN IRRITATION/CORROSION

White Newzeland rabbits were used to test Malachite Green for the skin irritation potential: after application of 500 µl rabbits were observed for 1h, 24h, 48h, 72 hours up to 8 days. Erythema was not identified because the skin resulted to be colourful, while no oedema was found. However, the rabbit skin was dry and atrophied, even after 8 days of observation, thus the substance was evaluated as strong irritating (DyStar Colours Distribution GmbH, 1982). Despite the experiment was performed according to accepted testing guideline, details about the tested substance composition are missing. The effects recorded were not fully evaluable and the recovering has been evaluated after only 8 days instead than 21 days. Furthermore, dryness is not clearly an irritating effect attributable to the test substance. Because of the lacking of relevant information from the assessment point of view, the study has been disregarded.

As mentioned into the IUCLID section 7.2.3, Clemmensen et al. (1984) tested the dermal acute toxicity of Malachite Green (MG) oxalate (purity > 90 %). The limited information available suggests application of a 20 % suspension of Malachite Green oxalate (2000 mg/kg) does not cause skin irritation: it did not produce visible erythema or oedema on either rats or guinea pigs.

In conclusion, a classification of Malachite Green as skin irritating would be not justified.

EYE/IRRITATION

Clemmensen et al. (1984) tested eye irritation by Malachite Green Oxalate. Instillation of 8 % aqueous solution produced market oedema, substantial discharge and slight hyperemia of the conjunctiva, which disappeared after 24 h in two out of three rabbits. Treatment with fine crystals of Malachite Green produced a totally opaque corneas, bright red and oedematous conjunctivae up to four days. An harmonized classification and labelling (C&L) has already been approved for Malachite Green chloride (EC: 209-322-8) and oxalate (EC: 219-441-7) salts. The classifications have been discussed by Commission of the European Communities and the related information was presented in ECBI/54/02 report, 18th July, 2002 (Health and Safety Executive, UK. 2005). In this context, the Clemmensen et al. study outcomes have been reviewed and the effects occurring in the rabbit treated with fine crystals were judged assufficient to support the current classification: Xi; R41 (corresponding to Eye Dam. 1, H318 of the CLP Regulation (EC 1272/2008).

An epidemiological investigation was performed in 2005: eyewash fluid collected from the patients exposed to the colors was also subjected for analysis. The study was further extended to evaluate the corneal penetration of Malachite Green using goat cornea in perfusion chamber. In was concluded that the usage of Malachite Green cause severe form of ocular manifestations upon its exposure. Trans-corneal penetration studies revealed lack of detectable concentration of Malachite Green in the aqueous humour at the studied concentration showed that it is unlikely to cause intraocular toxicity (Velpandian, 2007).

Furthermore, literature sources reports a case in which 1 % solution of Malachite Green resulted in destructive keratinis with hypopyon (hypopyon is pus in the eye; it is a leukocyte exudate, seen in the anterior chamber, usually accompanied by redness of the conjunctiva) and terminated in bilateral blindness due to corneal opacification. In the same book, Malachite Green is reported to cause injury ranging in severity from conjunctiva oedema, hyperemia, purulent discharge to total opacification of corneal stroma (Grant, 1974)

Despite the DyStar Colours Distribution GmbH (1982) study reports conclusions that are in agreement with the abovementioned information, it cannot be considered for the classification and labelling pourpose. The experiment is scientifically acceptable, nevertheless details about the tested substance composition are missing; because of the lacking of relevant information, the study has been disregarded.

In conclusion, all available information confirm that Malachite Green cause severe irritation.

REFERENCE

Grant, W.M. 1974. Toxicology of the Eye. 2nd ed., pp. 430-433. Charles S. Thomas, Springfield, IL. p.431

Effects on eye irritation: highly irritating

Justification for classification or non-classification

According to the CLP Regulation (EC 1272/2008), 3.2 Skin corrosion/irritation section, skin irritation means the production of reversible damage to the skin following the application of a test substance for up to 4 hours.

Based on the available information, a classification of Malachite Green as skin irritating would be not justified.

According to the CLP Regulation (EC 1272/2008) substances that have the potential to induce serious eye damage are classified in Category 1. The available information shows that Malachite Green can cause serious eye damage.

In conclusion, the substance is not classified for the skin irritation. On the contrary, it is classified as Eye. Dam. 1 (H318), according to the CLP Regulation (EC 1272/2008).