Pentasodium 4-amino-6-[[5-[(4-amino-6-chloro-1,3,5-triazin-2-yl)amino]-2-sulphonatophenyl]azo]-3-[(2,5-disulphonatophenyl)azo]-5-hydroxynaphthalene-2,7-disulphonate

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

1.Persistence Assessment:

Based on the data of two tests (Ready biodegradability test - Modified MITI - ISO 5815; and Inherent biodegradability – Zahn-Wellens -OECD TG 302 B) the test substance FAT 40171 can be concluded to be not-biodegradable and stable in the environment. A hydrolytic stability test, performed on a similar substance FAT 45168 as a function of pH in aqueous solution was performed according to OECD guideline 111 method C.7(440/2008) concluded that the read across substance FAT 45168/A at pH 4.0 and 25 °C was estimated to be relative slow (t1/2 (25 °C) = about 100 days). Also, the adsorption to soil and sludge was tested using the HPLC method, the outcome indicates that the test substance does not sorb strongly to soil and sludge and can be regarded as mobile.

2.Bioaccumulation Assessment:

The partition coefficient n-octanol/water of FAT 40171 at 20 °C, from the individual solubility in water and n-octanol, was determined to be log Pow = -3.96 According to the screening criteria for bioaccumulation (B for bioaccumulative, vB for very bioaccumulative) given in the technical guidance provided by ECHA (ECHA 2008, Guidance on information requirements and chemical safety assessment, Chapter R.11), a substance does not fulfil the B and the vB criterion if its log Kow ≤ 4.5. The octanol-water partition coefficient for the test item is log Pow = -3.96

This value is much below the threshold value of log Kow ≤ 4.5. Considering the low water solubility value and further looking at the influence of lipid solubility on the bioconcentration of hydrophobic compounds and demonstrated a decrease in lipid solubility with increasing Kow values (Chessells et al. (1992)) for superhydrophobic compounds (log Kow >6), it can be assumed that it will led to reduced BCFs. In conclusion, the substance is regarded as not bioaccumulative neither fulfilling the B nor the vB criterion.

3.Toxicity Assessment:

No long-term studies for marine or freshwater organisms are available. Therefore, based on current knowledge, the substance does not fulfil the T criterion based on the PBT criteria according to Annex XIII of the REACH Regulation.

According to the screening criteria provided by ECHA (ECHA 2008, Guidance on information requirements and chemical safety assessment, Chapter R.11), a substance has to be considered to fulfil the criteria for toxicity (T for toxicity) if the EC50 or LC50 of a short-term aquatic toxicity test is below 0.1 mg/L. For the substance under consideration, the following EC50/L50 values were obtained: Aquatic toxicity studies in Fish, Invertebrates, Algae and Microorganisms were performed as per standard guidelines to evaluate the toxicity potential of the test substance the test substance. Three Aquatic toxicity studies in Fish were performed and the LC50 value noted at the end of 96 hour exposure period to the test substance was >1000 mg/L. Two test evaluated for toxicity to Daphnia showed 48 hour EC50 value as 183.1 mg/l.

Data from a read across study showed 72-hours EC50 (Biomass) and EC50 (Growth rate) for FAT 45'168/A as clearly higher than 100 mg test substance/L when based on the real toxic effect. NOEC value for both 72-hours EC50 (Biomass) and EC50 (Growth rate) was recorded as 1 mg/L.

For microorganisms, studies conducted using sludge from a domestic wastewater treatment plant reported under the test conditions, the 3 h IC50 as >320 mg/L.

Based on the test data for all the three species (LC50 and EC50>100 mg/L) FAT 40171 can be classified as Not Toxic to aquatic organisms.

There is no evidence of chronic toxicity from the available 28-day repeated dose mammalian toxicity test. Based upon the results obtained in this study, the "no-observed-adverse-effect level" of FAT 45'168 / A is 50 mg/kg body weight for male and female rats when administered orally by gavage for a period of 28 days. The substance is neither classified as carcinogenic, mutagenic or toxic for reproduction.