Dimethylammonium 2,4-dichlorophenoxyacetate

Endpoint summary

Description of key information

Skin irritation
Kita, 1997, Aminopielik 720, skin irritation, RL2 – not irritating
Key, Kita, 1991, Aminopielik 600, RL1 – not irritating
Eye Irritation
Key, Kita, 1997, Aminopielik 720, eye irritation, RL2 – irritating
Kita, 1991, Aminopielik 600, eye irritation, RL2 – irritating

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

The irritating potential of dimethylammonium 2,4-dichlorophenoxyacetate (CAS 2008-39-1) was tested in studies conducted according to OECD Guideline 404 (skin irritation/corrosion) and OECD Guideline 405 (eye irritation).

 

Skin Irritation

Dimethylammonium 2,4-dichlorophenoxyacetate (CAS 2008-39-1) was tested for skin irritation potential according to OECD Guideline 404 (Key, Kita, 1991, Aminopielik 600, RL1): The shaved back of three New Zealand White rabbits was exposed to 0.5 mL test material for 4 hours under occlusive conditions. Thereafter, the rabbits were observed for 72 h after exposure and skin reactions were assessed using the Draize scheme periodically after removal of the patch. No signs of erythema and oedema were observed during the study period.

Another study was conducted analogously (Kita, 1997, Aminopielik 720, skin irritation, RL2). Again, the dorsal area of the trunk was exposed to 0.5 mL test material for 4 hours under occlusive conditions and animals were observed for 72 h subsequently. Whereas no original data was available, the primary dermal irritation index (PDII) was 1.6.

 

Eye Irritation

Two studies were conducted with the test substance (Dimethylammonium 2,4-dichlorophenoxyacetate (CAS 2008-39-1)) according to OECD Guideline 405.

In the first study, 0.1 mL of the test material was instilled into the conjunctival sac of one eye of one New Zealand White rabbit. Due to the expected corrosiveness of the test substance, only one animal was used. The animal was observed for 7 days and irritation was scored 24 h, 48 h and 7 days after instillation according to the method of Draize. In deviation from the guideline, the 72 h time point was not evaluated and the animal was observed for only 7 days after application. The test substance caused irritant effects in cornea, iris and conjunctivae at all time points of examination. Opacity covered nearly the whole area of the cornea. The iris was not discernible; it was congested and did not react to light. In the conjunctivae, diffuse beefy red hyperemia was observed and the lids were swollen about half closed. After 48 h necrosis of the mucosa and after 7 days leukoma were observed. The mean scores were: cornea score: 3, iris score 2, conjunctivae score: 3 and chemosis score: 3. These effects were not reversed until the end of the observation period. In addition to that, three animals were exposed to a 1% dilution of the test substance without any adverse effects (Key, Kita, 1997, Aminopielik 720, eye irritation, RL2).

A second study, again conducted according to OECD Guideline 405, resulted in analogous results. 0.1 mL of the test material was instilled into the conjunctival sac of one eye of three New Zealand White rabbits. The animals were observed for 7 days and irritation was scored 24 h, 48 h and 7 days after instillation according to the method of Draize. In deviation from the guideline, the 72 h time point was not evaluated and the animal was observed for only 7 days after application. The test substance caused irritant effects on cornea, iris and conjunctivae. In the cornea a diffuse area of opacity to a discernible translucent area of one quarter was observed. In the conjunctivae hyperemia of the blood vessels and an obvious swelling were noted. The mean scores were: cornea score: 0.83, iris score 0.83, conjunctivae score: 1.5 and chemosis score: 1.5. Although the intensity of these lesions diminished with the passage of time, the effects were not fully reversible until the end of the observation period. Again, the study conducted in parallel with a 1% solution of the test substance caused no irritation of the eyes (Kita, 1991, Aminopielik 600, eye irritation, RL2).

 

Taken together, these data indicate that dimethylammonium 2,4-dichlorophenoxyacetate (CAS 2008-39-1) is not irritant or corrosive to the skin but is strongly irritating to the eye.

Effects on eye irritation: highly irritating

Justification for classification or non-classification

According to the DSD and CLP criteria for classification and labelling of dangerous substances dimethylammonium 2,4-dichlorophenoxyacetate (CAS 2008-39-1) is not classified as skin irritant.

According to the DSD (67/548/EEC) criteria for classification and labelling of dangerous substances dimethylammonium 2,4-dichlorophenoxyacetate (CAS 2008-39-1) is classified as severe eye irritant.

According to CLP (EC No. 1272/2008) criteria for classification and labelling of dangerous substances dimethylammonium 2,4-dichlorophenoxyacetate (CAS 2008-39-1) is classified to Category 1 (irreversible effects on the eye).