Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Short-term toxicity to fish

In accordance with column 2 of Annex VIII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the substance is highly insoluble (solubility: 0.05445 mg/L at 25° C) in water as per the authorative handbook data source.

Short-term toxicity to aquatic invertebrates

In accordance with column 2 of Annex VII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the substance is highly insoluble (solubility: 0.05445 mg/L at 25° C) in water as per the authorative handbook data source.

Toxicity to aquatic algae and cyanobacteria

In accordance with column 2 of Annex VII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the substance is highly insoluble (solubility: 0.05445 mg/L at 25° C) in water as per the authorative handbook data source.

Toxicity to microorganisms

The test substance inhibited the growth of Clostridium perfringens and Lactobacillus rhamnosus with decreased cell numbers of 35% and 47% at 6 hr and 17% and 39% at 10 hr, respectively. Growth of Enterococcus faecalis was inhibited with a decreased cell number value of 11% at 6 hr.At the end the minimum inhibition concentration (MIC) considered to be 27.357 mg/l on the basis of Decrease in number of bacterial cells.

Additional information

Short-term toxicity to fish

In accordance with column 2 of Annex VIII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the substance is highly insoluble (solubility: 0.05445 mg/L at 25° C) in water as per the authorative handbook data source.

Short-term toxicity to aquatic invertebrates

In accordance with column 2 of Annex VII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the substance is highly insoluble (solubility: 0.05445 mg/L at 25° C) in water as per the authorative handbook data source.

Toxicity to aquatic algae and cyanobacteria

In accordance with column 2 of Annex VII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the substance is highly insoluble (solubility: 0.05445 mg/L at 25° C) in water as per the authorative handbook data source.

Toxicity to microorganisms

By applying weight of evidence approach to two studies which includes experimental results from peer reviewed journal for micro organism toxicity of test chemical 1- (2, 4-dimethylphenylazo)-2-naphthol i.e Sudan II (Cas no. 3118-97-6) were summarized as follows:

First study from peer reviewed journal Anaerobe, Vol. 18, Pg. no. 445-453, 2012 indicate Toxicity study of micro-organism to the test substance was conducted using 11 different human intestinal bacteria.When test bacteria was exposed to the test substance Sudan II, the growth ofC. perfringensandL. rhamnosuswas inhibited with decreased cell numbers of 35% and 47% at 6 hr and 17% and 39% at 10 hr, respectively. Growth ofE. faecaliswas inhibited with a decreased cell number value of 11% at 6 hr.The Data (bacterial cell numbers) are presented as mean of triplicate with standard deviations (SD) of<5%.Pvalues<0.05.The bacterial isolates were preserved at -80ᵒC in 15% glycerol stocks.The bacterial cell number was analyzed on an Accuri C6flow cytometer (FCM) (Accuri Cytometers), with 488 nm excitation from a blue solid state laser at 50mW and the standardfilter setup at 6 and 10 hr incubation times.Only slight inhibition of the growth of bacterial isolatesB. ovatus, B. infantis, B. catenulatum, C. indolis,C. ramosum, E. coli,P. magnus and R. obeum respectively were observedat 6 and 10 hr incubation times.Significant inhibition in growth was seen of bacterial isolates such as C. perfringens, L. rhamnosusandE. faecalis. The minimum inhibition concentration (MIC) considered to be 27.357 mg/l on the basis of Decrease in number of bacterial cells.

And another peer reviewed journal APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Vol. 73, No. 23, Pg. no. 7759–7762, Dec. 2007 for target suggest the toxicity study of micro-organism to the test substance was conducted using human intestinal microflora.When test bacteria was exposed to the test substance Sudan II, a lag phase of 2 to 4 hrs was observed. Final cell density in the medium containing the test substance was found to be about 90%.The MIC value for human intestinal microflora was found to be 10 mg/l. Thus, Sudan II has moderate inhibition effect on the human intestinal microflora indicating that the dye was not toxic to the human intestinal microflora.

Both available studies give the the minimum inhibition concentration (MIC) is in the range 27.357 mg/l to 10 mg/l which indicate the moderate inhibition effects.