4,11-diamino-2-[3-(2-methoxyethoxy)propyl]-1H-naphth[2,3-f]isoindole-1,3,5,10(2H)-tetrone

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 36152/N can be concluded to be not-biodegradable and stable in the environment. A hydrolytic stability test, performed as a function of pH in aqueous solution was performed according to OECD guideline 111 method C.7(440/2008) concluded that hydrolysis as a function of pH could not be determined since the water solubility of test substance FAT 36152 was very low.

 

2.Bioaccumulation Assessment:

The partition coefficient n-octanol/water of FAT 36152/M at 20 °C, calculated based on the individual solubility in water and n-octanol, was determined to be log Pow ≥4.44. 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 ≥4.44.

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:

Tests on acute oral toxicity demontrated the test substance to be not toxic. Data on acute dermal and acute inhalation toxicity are currently not available, but tests to determine skin and eye irritation and skin sensitization did not report any signs of systemic general toxicity when the test substance was applied on the skin or instilled in the conjunctival sac of the eye. A study conducted on a read-across substance according to OECD 422 resulted in an overall NOAEL of 150 mg/kg bw and day for systemic toxicity and in an NOAEL of 500 mg/kg bw and day for reprotoxic and developmental effects. Furthermore, the substance is neither classified as carcinogenic, mutagenic or toxic for reproduction.

Tests on acute aquatic toxicity have been performed on all three trophic levels. Acute toxicity to fish resulted in a LC50 value of >1000 mg/L at the end of 96 hour exposure period. Toxicity to Daphnia showed a 48 hour EC50 value of >100 mg/l and toxicity on Lemna minor was also found to be >100 mg/L.For microorganisms, studies conducted using sludge from a domestic wastewater treatment plant reported a 3 h IC50 as >320 mg/L.

No long-term studies for marine or freshwater organisms are available. Therefore, the test substance is regarded to be not toxic according to the screening criteria defined for toxicity assessment.

In summary, based on current knowledge, the substance should be regarded as persitent in the environment but it does neither fulfil the criterion to bioaccumulate nor does not fulfil the T criterion based on the PBT criteria according to Annex XIII of the REACH Regulation.