Disodium 5-acetylamino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate

Endpoint summary

Additional information

Stability

Hydrolysis

The chemical Acid red 1 is expected to hydrolyze to acids extremely slowly at 25 degC and pH7 since it has hydrolysable functional group amides.

With the exception of a few halogenated acetamides, most amides hydrolyze to acids extremely slowly at 25 degC and pH7.

Biodegradation

Biodegradation in water: screening tests

In the key study, Jahir Alam Khan (2011) studied the biodegradation of Azo Dye by Moderately HalotolerantBacillus megaterium.

The standard inoculums (25 ml) was used to inoculate 225 ml mineral salts basal media in which 15 ml of the dye solution has been added after autoclaving. The inoculated media was then incubated in shaking incubator at 150 rpm. Percentage dye degradation was determined spectrophotometrically every alternate day for twenty days.

Percentage dye degradation by the isolatedBacillus megateriumwas found to be 64.89% in 20 days. Under the test conditions, we can conclude that Red 2G is inherently biodegradable

In a supporting studies by Lata Kumari et al. (2016), BHUSSp X2 microbial strain was isolated from contaminated sites of carpet cluster Bhadhoi. The bacteria were used for the decolourization of effluent from dying plants of the cluster in Uttar Pradesh, India.

Within 24 hours, upto 97 % decolourization could be achieved at pH 8, temperature 35 °C under static condition, and initial concentration of 200 mg/l.

Similarly, under shaking conditions (100 rpm), upto 45 % decolorization could be achieved at pH 8, temperature 35 °C within 24 hours and initial concentration of 200 mg/l. This is possibly due to reduced activity of azoreductase with increase dissolved oxygen level under shaking conditions.

It can be concluded that under the test conditions RED 2G was found to be inherently biodegradable.

Biodegradation in water and sediment: simulation tests

Estimation Programs Interface (EPI) Suite (2016) prediction model was run to predict the half-life in water and sediment for the test compound Acid Red 1. Half-life period of Acid Red 1 in water is observed to be 60 days (1440 hrs.) while in sediment it is 541.667 days (13000 hrs). Based on these half-life values of Acid Red 1, it is concluded that the chemical is persistent in water and persistent in sediment

Biodegradation in soil:

EPI Suite has estimated that Acid Red 1 is expected to be found predominantly in soil and its persistence estimate is based on its transformation in this medium. Its half-life in soil, 120 days (720 hrs), does not exceeds the threshold as per Annex XIII of REACH but is borderline on the criteria of 120 days.

Therefore, Acid Red 1 is estimated to be not persistent in the soil environment.

Bioaccumulation

Bioaccumulation potential of the test chemical was estimated byBCFBAF v3.01 Program from EPISuite Version 4.1.

The estimated BCF value for the test chemical in fish was found to be 3.162 L/kg.

Based on the classification criterion for PBT, the test chemical was found to non- bioaccumulative. Transport and distribution

Adsorption / desorption

The adsorption capacity of the test chemical in soil was estimated using KOCWIN Program (v2.00) from EPISuite version 4.1. The koc was estimated using MCI method. The estimated Koc value for the test chemical is 20970L/kg

 

The test chemical has a corrected log Koc of 4.32. Based on this value it is concluded that the test chemical has strong sorption to soil and sediment, negligible to slow migration potential to ground water.