1,2-dihydro-6-hydroxy-1,4-dimethyl-2-oxo-5-[[3-[(phenylsulphonyl)oxy]phenyl]azo]nicotinonitrile

PBT assessment

PBT assessment: overall result

PBT status:

the substance is not PBT / vPvB

Justification:

1.Persistence Assessment:

Based on experimental data the test substance Disperse Yellow 114 can be concluded to be not-biodegradable and stable in the environment. The inherent biodegradability of the test substance was evaluated in a modified MITI (II) test conducted according to OECD Guideline 302C. At the end of 28 day 0 % biodegradation was noted. Disperse Yellow 114 is highly insoluble in water as shown in the test on water solubility (<0.7 μg/L). Thus, conducting the hydrolysis study is technically not feasible and is waived in line with criteria in Annex VIII, column 2 REACH. Koc was calculated using EPA tool EPI Suit and value of 27060 is considered for assessment. This means that Disperse Yellow 114 is immobile in soils. In conclusion, the substance should be regarded as only persistent (P) in the environment and not very persistent (vP) in the environment.

 

2.Bioaccumulation Assessment:

The partition coefficient n-octanol/water of the test item at 20 °C was calculated from the individual solubility in water and n-octanol and was determined to: log Pow ≥5.39

Considering the water solubility value and further looking at the influence of lipid solubility on the bioconcentration of hydrophobic compounds and/which 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 (test substance: log Kow >5.39). In conclusion, the substance is regarded as not bioaccumulative neither fulfilling the B nor the vB criterion.

 

3.Toxicity Assessment:

The substance is not harmful or toxic upon oral ingestion as demonstrated by acute oral tests. Also no acute systemic toxicity was observed when the substance was applied to the skin or the mucosa of animals for tests on skin and eye irritation and skin sensitisation. There is no evidence of chronic toxicity from the available read across (FAT 40543/A) oral repeated dose toxicity study is in rats (OECD 421). In an OECD 421 study the oral administration of similar substance FAT 40543/A to rats by gavage, at dose levels of 100, 300 and 1000 mg/kg bw/day was well tolerated. Based on limited evaluations for systemic toxicity the ‘No Observed Adverse Effect Level’ (NOAEL) was considered to be 1000 mg/kg bw/day. The ‘No Observed Effect Level’ (NOEL) for reproductive toxicity was considered to be 1000 mg/kg bw/day. The substance is not classified as carcinogenic, mutagenic or reprotoxic according to Regulation EC 1271/2008. No long-term studies for marine or freshwater organisms are available. Therefore, based on current knowledge, the substance does not fulfill 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 fulfill 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:

No long-term toxicity studies are available. The solubility of the substance is below <1 µg/L. The substance was difficult to get into solution even at 1 µg/L under testing conditions. Hence, based on the poor solubility of the substance testing was not feasible. Due to low water solubility of the test substance (<0.7μg/L), conducting the fish, algae, aquatic plants study was considered as not feasible. However,

an 48 hr test is available on Daphnia magna. Additionally, a study with toxicity to microbes is also available(3hr IC50 >1000 mg/l). Based on the available data from invertebrate and microorganism tests the test substance Disperse Yellow 114 can be considered as not toxic to aquatic species (EC50 >100 mg/l).