Reaction products of diazotised 4,4-diaminodiphenylamine-2-sulfonic acid, subsequently coupled with 6-amino-4-hydroxynaphthalene-2-sulfonic acid, further diazotised and coupled with metaphenylendiamine, sodium salts

Endpoint summary

Description of key information

Oral toxicity:      LD50 > 2000 mg/kg bw

Dermal toxicity: LD50 > 2000 mg/kg bw

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

Direct Black 22 (DBk22) is not toxic by oral, dermal and inhalation route under short-term exposure. All the available studies  confirm that DBk22 is not toxic up to the highest tested dose.

Acute oral

DBk22 was tested on rats for oral acute toxicity according to Directive 67/548/EEC at a singular dose of 2000 mg/kg; no mortality was observed and no abnormalities were recorded during the test period (Castells, 2000). The result does not permit to establish the LD50 for the substance, nevertheless all other reported studies in read across confirm that DBk2 is not toxic at limits fixed for classification according to CLP regulation.

Acute inhalation

Based on REACH regulation annex VIII column 2 (specific rules for adaptation from column 1) in addition to the oral route (8.5.1), for substances other than gases, the information mentioned under 8.5.2 to 8.5.3 shall be provided for at least one other route. The choice for the second route will depend on the nature of the substance and the likely route of human exposure.

Particle size distribution study (Nebuloni, 2012) reported that DBk22 is characterized by particles that are expected to remain in the upper respiratory tract, that is characterized by efficacious defence mechanisms able to remove them. From this point of view inhalation route is expected to be an unlikely route of absorption of the substance.

Acute dermal

The study was performed on a structural analogue of DBk22, and reported an LD50 > 2000 mg/kg. The dye is non-toxic and this conclusion can also be read acroos to DBk22, considering the similar overall toxicological behaviour.

Justification for selection of acute toxicity – oral endpoint

Study well conducted, according to scientifically recognized method; the substance was tested at an adequate concentration to evaluate the acute oral toxicity.

Justification for selection of acute toxicity – inhalation endpoint

Based  on REACH regulation annex VIII column 2 (specific rules for adaptation from column 1) in addition to the oral route (8.5.1), for substances other than gases, the information mentioned under 8.5.2 to 8.5.3 shall be provided for at least one other route. The choice for the second route will depend on the nature of the substance and the likely route of human exposure.

Particle size distribution (R&C, 2012) showed that DB22 is characterized by particle that are expected to remain in the upper respiratory tract, that is characterized by efficacious defence mechanisms able to remove them. From this point of view inhalation route is expected to be an unlikely route of absorption of the substance.

Justification for selection of acute toxicity – dermal endpoint

Study well conducted, reliable and developed according to the official guidelines. Proper read-across from supporting substance.

Justification for classification or non-classification

Direct Black 22 (DBk22) does not meet the criteria to be considered an acutely toxic substance.

According to CLP regulation (EC1272/2008) DBk22 is not classified for oral/inhalation/dermal Acute toxicity.