Benzenamine, reaction products with aniline hydrochloride and nitrobenzene

Endpoint summary

Additional information

Summary of degradation

 

The substance can be considered as not readily biodegradable (4% after 28 days) according to an OECD 301C Modified MITI test (I) (Handley et al. 1993). The water solubility of Nigrosine is less than 0.1 mg/L at 20ºC (Connor & Mullee 2007).

 

Simulation testing on ultimate degradation in surface water

 

In the OECD 309 (Feng, 2020) test conducted, the degradation of the test material was slow in surface water. The rate of degradation (DT50) of the test material over 60 days of incubation at 12 ± 2°C was determined to be 72.5 (low dose) to 362 days (high dose) (SFO model).

 

Minimal 14CO2 production (at most 0.1% AR) was observed in the high and low dose samples, demonstrating that the mineralisation of the test material was not concentration dependent (Feng, 2020).

Identification of degradation products (Annex IX, 9.2.3) is not relevant.

 

Volatilisation

 

In an OECD TG 104 test the vapour pressure of the test substance was determined to be 1.1x 10-10 Pa at 25 ºC (Tremain, 2007).

 

Distribution modelling

 

No distribution modelling data exist. Summary of environmental distribution Using the HPLC screening method (OECD 121) the log KOC value was determined to be in the range of 0.842 to > 5.63 (Connor & Mullee 2007). 61.4% (percentage area normalised) had a log KOC >5.63. Based on the normalised percentage per peak a weighted average log KOC of 4.67 corresponding to a KOC of 46753 was calculated. Summary and discussion of bioaccumulation The log KOW of the test material has been determined to be in the range of 0.518 and > 6.50 (Connor & Mullee 2007). 96.2% (percentage area normalised) had a log KOW >3 and 39.2% a log KOW>6.5. Based on the normalised percentage per peak a weighted average log KOW of 5.23 was calculated. A bioconcentration factor for Cyprinus carpio is available (NITE website, CHRISP). The BCF ranges between 7.9 to 41 mg/L (highest test concentration of 0.1 mg/L) and between 25 and 164 mg/L at the low test concentration (0.01 mg/L). The average lipid content was 3.6%. The highest BCF of 164 L/kg was converted to 216 L/kg at 5% (lipid normalisation according to OECD TG 305).

Additionally, log Kow and BCF values were calculated in EPISUITE (v. 4.11) for 22 components of the substance. These components are believed to be those making up Peak 3 – the peak that is considered the worst-case in terms of bioaccumulation potential based on the results from the bioaccumulation test. The calculated Log Kow values for these components range from 1.77 to 14.95 and BCF values range from 3.16 to 17100 L/kgwwt. Specifically:

•       Compounds No. 27b, 30, 33, 36a, 36b and 38 had Log Kow >10, BCF < 2000 L/kg wwt and molecular weights > 700 – therefore these compounds are not considered B/vB;

•       Compound No. 3 had a Log Kow < 4.5 and a BCF < 2000 L/kg wwt – therefore this compound is not B/vB;

•       Compounds No. 12b, 16, 22, 28b and 35 had Log Kow > 4.5 and BCF < 2000 L/kg wwt – based on the Log Kow, these compounds are potentially B/vB;

•       Compounds No. 5, 10a, 26 and 29 had Log Kow > 4.5 and BCF > 2000 L/kg wwt but < 5000 L/kg wwt – therefore these compounds are B but not vB;

•       Compounds No. 6, 8a, 8b, 9, 11b and 17 had Log Kow > 4.5 and BCF > 5000 L/kg wwt – therefore these compounds are B and vB.

Since a significant number of the components in Peak 3 potentially fulfilled the B/vB criteria, the substance is regarded as being potentially B and vB.

The report ” 1105411.UK0 - 4219 QSAR Estimation of the Bioaccumulation Potential of Components of Nigrosine (EC 309-912-6)” is attached at section 13.2 of this dataset.

Therefore it can be concluded that certain components within the substance hava a potential to bioaccumulate.

 

Secondary poisoning

 

Bioaccumulation of certain components contained within the substance is possible. Hence secondary poisoning risk exists for those components.