Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium

Endpoint summary

Description of key information

Biodegradation in water:

Biodegradability of test chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium (CAS no. 90294-36-3) was estimated by using OECD QSAR tool box v3.4 by considering six closest read across chemical log Kow as primary descriptor. Percent biodegradation of the test chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium was estimated to be 0.5 % by considering BOD as parameter and Microorganism as inoculum in 28 days. On the basis of percent degradability value it can be concluded that test chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium is not readily biodegradable.

Additional information

Biodegradation in water:

Predicted data study for target chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium (CAS no. 90294-36-3) and experimental studies for its structurally similar read across chemicals have been conducted and their results are summarized below for biodegradation in water endpoint.

In a predicted data study the biodegradability of test chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium (CAS no. 90294-36-3) was estimated by using OECD QSAR tool box v3.4 by considering six closest read across chemical log Kow as primary descriptor. Percent biodegradation of the test chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium was estimated to be 0.5 % by considering BOD as parameter and Microorganism as inoculum in 28 days. On the basis of percent degradability value it can be concluded that test chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium is not readily biodegradable.

Next study was experimental study done from The Journal of Toxicological Sciences, (1978). The aim of the study was to estimate the microbial decomposition of Acid yellow 23 dye. 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 in a day for 10 days. 20% decomposition of test chemical was obtained in 10 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 acid yellow 23 is not readily biodegradable under aerobic conditions.

One more study has been done for same read across chemical as mentioned in above experimental study from journal Chemosphere Vol 22 (1991) in this study the Biodegradability of read across chemical trisodium 5-hydroxy-1-(4-sulphophenyl)-4-(4-sulphophenylazo)pyrazole-3-carboxylate (Acid yellow 23) was determined by anlysing percent recovery of read across material. This read across material is dye and inoculums used for biodegradation was obtained from Screened raw waste water from greater Cincinnati Mill Creek sewage treatment plant was used as influent (INF) to three pilot scale activated sludge biological treatment systems (Two experimental and one control). Each system consists of primary clarifier, complete mix aeration basin and secondary clarifier. Influent was spiked with read across material at concentration of 1 mg/L and 5 mg/L. Then Dye analytical studies were conducted by purified dye compound in organic free influent waste water and mixed liquor. Then influent, primary influent filtrate was passed through column packed with resin. The filter paper and resin were soaked in an ammonia – acetonitrile solution and then soxhlet extracted with ammonia – acetonitrile. The extract was concentrated and brought upto 50 ml volumn with methanol/dimethyl formamaide solution. All extracted samples were analyzed by HPLC with ultraviolet detector. Percent recovery determined was 107 % in low spiked and 103 % in high spiked. On the basis of percent recovery value biodegradation of dye was negligible i.e., 0%. Percent biodegradation of read across chemical trisodium 5-hydroxy-1-(4-sulphophenyl)-4-(4-sulphophenylazo)pyrazole-3-carboxylatewas observed to be 0.0 % by test material analysis by HPLC parameter. On the basis of percent degradation it is concluded that this read across material is not readily biodegradable.

Last experimental study was done for another read across chemical Disodium 4,4'-bis(2-hydroxynaphthalen-1-ylazo)biphenyl-2,6'-disulphonate(Acid red 97) in this study the aerobic biodegradation experiment was performed for chemical Disodium 4,4'-bis(2-hydroxynaphthalen-1-ylazo)biphenyl-2,6'-disulphonate(Acid red 97) (CAS no.10169 -02 -5) using activated sludge at concentration 0.5 g/L dry material as inoculums and initial concentration of chemical taken was 100mg/L for 42 days. By considering DOC removal parameter read across chemical showed 17% degradation in 42 days. The read across chemical Disodium 4,4'-bis(2-hydroxynaphthalen-1-ylazo)biphenyl-2,6'-disulphonate belongs to D category according to table 1 and 2 as its limit value falls in that range. This percentage value is very less So it is concluded that Disodium 4,4'-bis(2-hydroxynaphthalen-1-ylazo)biphenyl-2,6'-disulphonate(CAS no. 10169 -02 -5) is not readily biodegradable.

On the basis of results of all the studies mentioned above for target chemical Chromate(2-), [4-[4-[(5-chloro-2-hydroxyphenyl)azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulfonato(3-)][4-[(5-chloro-2-hydroxyphenyl)azo]-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)]-, sodium (CAS no. 90294-36-3) as well as for its structurally similar read across chemicals it can be concluded that test chemical is not readily biodegradable.