Disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate

Endpoint summary

Description of key information

Biodegradation in water:
The test item disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) undergoes 2.80 % biodegradation after 28 days in the test condition. Thus, the test item can be inferred/considered as not readily biodegradable.

Biodegradation in water and sediment:
Half-life period of Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), in water is observed to be 60 days (1440 hrs.) while in sediment it is 541.66 days (13000 hrs). Based on these half-life values of Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), it is concluded that the chemical is persistent in water and sediment.

Biodegradation in soil:
EPI Suite has estimated Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), is expected to be found predominantly in soil and it’s persistence estimate is based on its transformation in this medium. Its half-life in soil is estimated to be 120 days (2880 hrs). Therefore, Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), is estimated to be persistent in the soil.

Additional information

Biodegradation in water:
Data available for target Disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate for the endpoint Biodegradation in water are summarized as follows:

In key study, 28-days Manometric respirometry test following the OECD guideline 301F was conducted to determine the ready biodegradability of disodium 4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate(CAS No. 4553-89-3). The test system included control, test item and reference item. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 100mg/L, while that of inoculum was 10ml/l. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % Degradation was calculated using the values of BOD and ThOD for test item and reference item. The BOD28value of disodium-4,4'-[[2,4-dihydroxy-5-(hydroxymethyl)-1,3-phenylene]bis(azo)]bisnaphthalene-1-sulphonate (CAS No. 4553-89-3) was observed to be 0.0385 mgO2/mg. ThOD was calculatedas 1.373 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to manometric respirometry test was found to be 2.80%. Based on the results, the test item, under the test conditions, was found to be not readily biodegradable at 20 ± 1°C over a period of 28 days.

In supporting study, Estimation Programs Interface Suite (EPI suite, 2017) was run to predict the biodegradation potential of the test compound Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), CAS No. 4553-89-3, in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that the test chemical Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) is not expected to be readily biodegradable.

Thus based on available data for target it is concluded that Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate) is not expected to be readily biodegradable in water.

Biodegradation in water and sediment:
Half-life period of Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), in water is observed to be 60 days (1440 hrs.) while in sediment it is 541.66 days (13000 hrs). Based on these half-life values of Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), it is concluded that the chemical is persistent in water and sediment.

Biodegradation in soil:
EPI Suite has estimated Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), is expected to be found predominantly in soil and it’s persistence estimate is based on its transformation in this medium. Its half-life in soil is estimated to be 120 days (2880 hrs). Therefore, Disodium 4,4’-(2,4-dihydroxy-5- hydroxymethyl-1,3-phenylene bis-azo) di- (naphthalene-1-sulfonate), is estimated to be persistent in the soil.