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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability :

Phototransformation in air:-

The atmospheric oxidation half-life of 4-aminoazobenzene-3,4'-disulphonic acid was estimated using the level III multimedia model. It was estimated that the substance is not persistent in air medium as the half life period of 4-aminoazobenzene-3,4'-disulphonic acid in air is only 1.7 days. This indicates that 4-aminoazobenzene-3,4'-disulphonic acid is rapidly phototransformed in air.The hydroxyl radical reaction rate constant is estimated to be 0.0000000000096 cm3/molecule-sec at 25 degrees C.


Half life


Percent in Medium




Biodegradation :

Biodegradation in water:-

A number of studies and predicted data for the test compound4-Aminoazobenzene-3,4'-disulfonic acid (CAS no. 101-50-8)and its read across substance were reviewed for the biodegradation end point which are summarized as below:


Biodegradation study (A. Paszcyzynski et. al: 1991) of test substance4-Amino-1,1’-azobenzene-3,4'-disulfonic acid (acid yellow 9) was performed using 15 differentStreptomyces spp. for 14 days.The test was performed using 15 differentStreptomyces sppas an inoculum. The test substance conc. used is 50 mg/l.

EachStreptomyces spp. was grown in a cotton-plugged 250 ml flask containing 25 ml of the following medium: 0.2 M Tris buffer (pH 7.6) 100 ml, 1.0g vitamin-free Casamino acids, 100 µg thiamine, 100 µg biotin, 2 g D-glucose, 900 ml deionized wate. Thiamine, biotin, and D-glucose were filtersterilized and added to the autoclaved medium. The dye was filter sterilized and added at 0.005% (w/v) to the autoclaved basal medium. Cultures were incubated at 37ᵒC for 14 days with shaking (200 rev min1). Three replicates for each strain grown in only the basal medium were incubatedas well.Degradation of test substance was determined by spectrophotometrically and by using HPLC.Degradation of the test substance was confirmed by HPLC. A Hewlett-Packard HP 1090 Liquid Chromatograph equipped with a HP 40 diode array UV-VIS detector and automatic injector was used. The chromatograph was controlled by an HP 9000 series 300 computer which used HP 7995 A ChemStation software. A reverse phase column from Phenomenex (Rancho Palos Verdes, CA, type Spherex 5C 18 size 250 × 2.0 mm, s/no PP/6474A) was used. Each 15-min analysis used a solvent gradient of acetonitrile (solvent A) and 10mM DMS buffer pH 4.5 (solvent B), with the following conditions: 0-5 min, 100% A; 5-12 min, 25% A, 75% B; 12-15 min, 100% B; post time 2 min, injection volume 10µl. Absorption was measured at 250, 325, 350, 400 and 450 nm, and spectra were collected automatically by the peak controller.Spectrophotometric assay was also carried out. A 1 ml sample of actinomycete culture medium was centrifuged and then diluted 2.5 fold with water. Azo dye substrate present was then measured spectrophotometrically (Hewlett-Packard 8452 diode array spectrophotometer operated by PC Vectra computer with HP’s MSTM-DOS/UV-VIS software).The percentage biodegradation of test substance was found to be 0% i.e; no degradation of test substance was observed by the 15 differentStreptomyces spp. Thus, the test substance was found to be non-biodegradable.




Estimation Programs Interface Suite (EPI suite) was run to predict the biodegradation potential of the test compound4-Aminoazobenzene-3,4'-disulfonic acid (CAS no. 101-50-8). The screening test inherent to the biodegradability of the substance was calculated using the software BIOWIN v4.10. The results indicate that4-Aminoazobenzene-3,4'-disulfonic acidis not expected to be readily biodegradable.




The aim of the study was to estimate the microbial decomposition of Food yellow 4 dye (Yasuhide TONOGAI et. al; 1978). The biodegradation of chemical was determined by 3 methods under aerobic conditions: Aerobic decomposition of dyes with sludge, Oxygen uptake and BOD determination. During 10 days of the aerobic experiment, the absorbance of dye solution was measured once day for 10 days. 20% decomposition of test chemical was obtained in10 days. 3.82 O2 mg/hg – sludge oxygen uptake was obtained in 5 –hrs test and the dissolved oxygen contents on the 5th day were essentially the same to initial ones. The low reactivity of aerobic sludge towards dyes was confirmed. Based on the results obtained from the aerobic degradation assay , Warburg method and BOD determination it can be concluded that tartrazine is not readily biodegradable under aerobic conditions.



The biodegradation study of test chemical Disodium 2-amino-5-[(4-sulphonatophenyl)azo] benzenesulphonate was performed for 28 days according to the OECD TG 302B (GSBL, 2016). Activated sludge was used as an inoculum. Parameter used for the biodegradation study was DOC removal. After 28 days, no degradation of test chemical Disodium 2-amino-5-[(4-sulphonatophenyl)azo]benzenesulphonate was observed. Thus, the test substance was found to be non-biodegradable.


On the basis of the overall reported resultsof target and its read across substance, it can be concluded thatthe substancewas found to be not-readily biodegradable.

Biodegradation in water and sediment:

Half-life period of 4-aminoazobenzene-3,4'-disulphonic acid in water is observed to be 37.5 days (900 hrs.) while in sediment it is 337.5 days (8100 hrs). Based on these half-life values of 4-aminoazobenzene-3,4'-disulphonic acid, it is concluded that the chemical is not persistent in water and persistent in sediment.

Biodegradation in soil:

Based on EPI prediction Level III Fugacity Model (Full-Output), the estimated half life period of 4-aminoazobenzene-3,4'-disulphonic acid in soil was obtained to be 75 days. Based on this half life value of4-aminoazobenzene-3,4'-disulphonic acid, it is concluded that the chemical is not persistent in the soil environment.

Bioaccumulation :

Bioaccumulation : Aquatic / Sediment

Bioaccumulation is the process by which the chemical concentration in an aquatic organism achieves a level that exceeds that in the water, as a result of chemical uptake through all possible routes of exposure. The relationship between bioaccumulation and bio-concentration is that, chemicals that have the potential to bioconcentrate also have the potential to bioaccumulate. Bioaccumulation is closely related to the Bioconcentration factor (BCF). 

The estimated bioconcentration factor (BCF) for 4-aminoazobenzene-3,4'-disulphonic acid is 3.2 which does not exceed the bioconcentration threshold of 2000. Thus it is concluded that 4-aminoazobenzene-3,4'-disulphonic acid is not expected to bioaccumulate in the food chain because it does not exceed the BCF criteria.

The supporting study also indicates that the BCF of 4-aminoazobenzene-3,4'-disulphonic acid to be 3.164 L/Kg indicating its non bioaccumulative nature.

Sr no

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Transport and Distribution :

Adsorption/Desorption :

By applying Weight of evidence approach for the target substance 4-aminoazobenzene-3, 4’-disulphonic acid (Cas no.101-50-8) studies are summarized as fallowed:

Both predicted sources i.e EPI Suite and PBT profiler indicate that the test substance4-aminoazobenzene-3, 4’-disulphonic acidhas a moderate sorption to soil and sediment and slow migration potential to groundwater. 

With following Koc values:

EPI SUITE - 871.3 (Log Koc=2.9401)

PBT profiler -870 (Log KoC=2.939)

Other weight of evidence studies for read across chemical from Scientific Bulletin journal (UPB Scientific Bulletin, Series B; Vol. 78, Iss. 1, 2016 P.137-148) indicate that the Soil adsorption test was conducted for test chemical tartrazine by using sorption floatation method.

Initial concentration of test chemical was 5-500 mg/L with pH range of 7-9 at temperature 20 deg C were selected to study tartrazine removal efficiency.

The removal efficiency of chemical tartrazine was found to be 9% using soil as adsorbent in sorption floatation technique.


 Overall all studies concluded that the test substance4-aminoazobenzene-3, 4’-disulphonic acid (Cas no.101-50-8)has a moderate sorption to soil.

Henry's Law constant :

Henry's law constant of 4-aminoazobenzene-3, 4’-disulphonic acid was estimated to be 0.000000000000000115 (1.15E-16 ) Pa m³/mol at 25 deg C