1-[(2-chloro-4-nitrophenyl)azo]-2-naphthol

Endpoint summary

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1962

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Purity unknown and method is only partially described.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

no

Species:

mouse

Route of administration:

oral: gavage

No. of animals per sex per dose:

10

Key result

Dose descriptor:

LD50

Effect level:

> 10 000 mg/kg bw

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 > 10,000 mg/kg bw

Executive summary:

Three out of ten mouse died from an acute exposure to 10 g/kg bw of C.I. Pigment Red 4.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Justification for type of information:

Category of Monoazo Red Pigments (C.I. PIGMENT RED 3, C.I. PIGMENT RED 4, C.I. PIGMENT ORANGE 5)

1. HYPOTHESIS FOR THE CATEGORY APPROACH
A very similar chemical structure is the basis for similar physical-chemical properties as very low solubility in water (but also in organic solvents and lipophilic matrices) and non-degradability which lead to inert behaviour and negligible bioavailability. See attached PR4_CSR.doc in Section 13 (1.1.1. Category Definition and its members - Category Hypothesis).

2. CATEGORY APPROACH JUSTIFICATION
Lacking bioavailability is probably the reason for the absence of any relevant mammalian toxicity. None of the category members showed a toxic effect after single oral or inhalational exposure, no skin or eye irritation, no skin sensitizing effect, and no mutagenic properties in any study (OECD 473, 476, 489) except in Ames assays (OECD 471). See attached PR4_CSR.doc in Section 13 (1.1.1. Category Definition and its members - Category Justification).

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Type of coverage:

semiocclusive

Vehicle:

arachis oil

Remarks:

BP

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg bodyweight.

Executive summary:

Mortality: There were no deaths.

Clinical Observations: Red/brown staining of the snout was noted in one male two hours after dosing. There were no other signs of systemic toxicity noted.

Dermal Irritation: Crust formation was noted at the test site of one female animal five and six days after dosing. No other signs of dermal irritation were noted.

Bodyweight: All animals showed expected gains in bodyweight over the study period.

Necropsy: No abnormalities were noted at necropsy.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Acute oral toxicity:

Acute toxicity after single oral application was tested in mice, which received 10,000 mg/kg bw . 3 of 10 mice died at the highest concentration of 10,000 mg/kg of C.I. Pigment Red 4.

Acute dermal toxicity:

A Study was conducted with C.I. Pigment Orange 5 in rats. The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg bw.

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.

Justification for selection of acute toxicity – oral endpoint
No acute oral toxicity has been observed in mice. Study with the highest reliability was selected.

Justification for classification or non-classification

Due to the findings described above (LD50 oral in rats >10,000 mg/kg bw) Pigment Red 3 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).

It can reasonably be deduced that Pigment Red 3 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/) and in the EU Classification Labelling and Packaging Regulation (1272/2008/EC), because

- Pigment Red 3did not cause lethal effects after administration of a single oral dose of up to 10,000 mg/kg in rats and mice,

- Pigment Red 3does not have to be classified as skin irritating, and

- it is unlikely that Pigment Red 3 becomes systemically bioavailable after skin contact due to its extremely low solubility in water and n-octanol.

Therefore, testing is not necessary to reach a scientific conclusion on classification.

It can reasonably be deduced that Pigment Red 3 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 3 did not cause lethal effects after administration of a single oral dose of up to 10,000 mg/kg in rats,

- Pigment Red 3 does not have to be classified as skin irritating, and

- it is unlikely that Pigment Red 3 becomes systemically bioavailable after inhalation due to its extremely low solubility in water and n-octanol.

Therefore, it is concluded that Pigment Yellow 74, when aerosolized, is an inert dust and that testing is not necessary to reach a scientific conclusion on classification.

Furthermore, Pigment Red 3 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.