3-hydroxy-N-(o-tolyl)-4-[(2,4,5-trichlorophenyl)azo]naphthalene-2-carboxamide

Endpoint summary

Description of key information

Acute oral toxicity:
The test item (Pigment Red 112) did not cause any mortality or significant clinical signs or necropsy findings after single oral gavage administration to male and female rats at 5000 mg/kg bw in a OECD guideline and GLP compliant study. The LD50 (male/female rat) was greater than 5000 mg/kg body weight (Hoechst, 1983). This key study is supported by further acute oral toxicity studies with Pigment Red 112 in which no lethal or other severe effects were reported at the highest dose tested of 10,000 mg/kg (Hoechst, 1979a; 1979b; Ciba-Geigy, 1972) or 15,000 mg/kg (Reseach Institute for Organic Syntheses, 2007).
Acute dermal toxicity:
The test item (preparation containing Pigment Red 112 at >90%) did not cause any mortality or significant clinical signs or necropsy findings after single dermal application to male rats at 5000 mg/kg bw in a OECD guideline compliant study. The LD50 (male rat) was greater than 5000 mg/kg body weight.
Acute inhalation toxicity: 
Study was waived; substance is not classified for this endpoint. When aerosolized in respirable form, the substance is considered likely to behave like an inert dust.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

5 000 mg/kg bw

Additional information

The test item (preparation containing Pigment Red 112 at >90%) did not cause any mortality or significant clinical signs or necropsy findings after single dermal application to male rats at 5000 mg/kg bw in a OECD guideline compliant study. The LD50 (male rat) was greater than 5000 mg/kg body weight. This study has some shortcomings, including that not a pure Pigment Red 112 was tested, but a preparation containing Pigment Red 112 at >90%. Also the study was not performed according to GLP guidelines and the English test report was reconstructed by the test institute from the study raw data and the original Czech report. However, the study is supported by the following reasoning that concludes that Pigment Red 112 does not exert systemic toxic effects after dermal application and thus does not have to be classified according to the criteria laid down in the EU Dangerous Substances Directive (67/548/EEC) and in the EU Classification Labelling and Packaging Regulation (1272/2008/EC):

- Pigment Red 112 did not cause lethal effects after administration of a single oral dose of up to 15,000 mg/kg in rats,

- Pigment Red 112 does not have to be classified as skin irritating, and

- it is unlikely that Pigment Red 112 becomes systemically bioavailable after skin contact due to its extremely low solubility in water and n-octanol.

 

Justification for classification or non-classification

Due to the findings described above (LD50 oral in rats >2000 mg/kg bw) Pigment Red 112 has not to be classified as acute orally toxic according to the criteria laid down in the EU Dangerous Substances Directive (67/548/) and in the EU Classification Labelling and Packaging Regulation (1272/2008/EC).

 

Due to the findings described above (dermal LD50 in male rats >5000 mg/kg bw) Pigment Red 112 has not to be classified as acute dermally toxic according to the criteria laid down in the EU Dangerous Substances Directive (67/548/) and in the EU Classification Labelling and Packaging Regulation (1272/2008/EC).

 

It can reasonably be deduced that Pigment Red 112 does not exert systemic toxic effects after acute inhalation exposure and thus does not have to be classified according to the criteria laid down in the EU Dangerous Substances Directive (67/548/) and in the EU Classification Labelling and Packaging Regulation (1272/2008/EC), because

- Pigment Red 112 did not cause lethal effects after administration of a single oral dose of up to 15,000 mg/kg in rats,

- Pigment Red 112 does not have to be classified as skin irritating, and

- it is unlikely that Pigment Red 112 becomes systemically bioavailable after inhalation due to its extremely low solubility in water and n-octanol.

Therefore, it is concluded that Pigment Red 112, when aerosolized, is an inert dust and that testing is not scientifically necessary.

 

Furthermore, Pigment Red 112 does not have to be classified for specific target organ toxicity – single exposure according to Regulation (EC) No 1272/2008, as no specific toxic effects were observed after acute exposure.