Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability :

Phototransformation in Air :

The atmospheric oxidation half life of phthalylsulfathiazole was estimated using level III multimedia model it indicates that phthalylsulfathiazole is not persistent in air medium as the half life period of phthalylsulfathiazole in air is only 0.15 days. From this it is concluded that phthalylsulfathiazole is rapidly phototransformed in air.

Hydrolysis :

The Hydrolysis rate constant of phthalylsulfathiazole was estimated to be 0.0000000000342882 cm3/molecule-sec. at half life of 3.743 Hrs.The estimated half life of the substance indicates that the substance is negligibly hydrolysable.

Phototransformation in Water :

No experimental data available. As this study is not a standard information requirement in REACH and there is no indication from the CSA on the need to investigate further the fate and behaviour of the substance (Annex X requirement), no further testing is considered necessary.

Phototransformation in Soil :

No experimental data available. As this study is not a standard information requirement in REACH and there is no indication from the CSA on the need to investigate further the fate and behaviour of the substance (Annex X requirement), no further testing is considered necessary.

Biodegradation :

Biodegradation in Water : Screening Test :

Based on level III fugacity model the half life period of Phthalylsulfathiazole was estimated. Phthalylsulfathiazole was 50% biodegradable in water in 38 days (half-life) indicating that phthalylsulfathiazole is readily biodegradable in water since the half life is less than the threshold of 60 days (to qualify the chemical as persistent)

Biodegradation in Water and sediment :

Based on level III fugacity model the half life period of phthalylsulfathiazole was estimated.Half life period of phthalylsulfathiazole in water was estimated to be 38 days while in sediment it is 340 days.Based on these half life values it is concluded that phthalylsulfathiazole is readily biodegradable in water where as it is non biodegradable in sediment. However, since there is no diffusion of the substance in the sediment as evident from the reported data (0% in sediment) and hence persistence in the sediment compartment is not likely to be critical.

Biodegradation in Soil :

Based on QSAR prediction half life period of phthalylsulfathiazole in Soil was estimated to be 99.2 days which exceeds the EPA criteria of 60 days

Also from the other weight of evidnece study it is found that the substance is 50% degradable in 75 days which also exceeds the EPA criteria of 60 days

Based on the above information it can be concluded that the substance is not readily biodegaradable and hence persistent in Soil according to CLPregulation.

Bioaccumulation :

Bioaccumulation : Aquatic/Sediment :

The estimated bioconcentration factor (BCF) for phthalylsulfathiazole by QSAR ,PBT profiler, EPI suit is 5.25 L/kg/wt , 3.2, 3.162 respectively, which does not exceed the EPA bioconcentration criteria of1000.

Based on the above valuesit can be concluded that the substance does not exceed the EPA bioconcentration criteria of1000 and therefore is non bioaccumulative in nature according CLPregulation.

Transport and distribution :

Adsorption/desorption :

Soil Adsorption Coefficient i.e Koc value of phthalylsulfathiazole was estimated as 685.1 (log Koc : 2.8357) at 25 deg C by means of MCI method. This indicates that phthalylsulfathiazole will moderately adsorb to the organic carbon fraction of the soil and will have a slow migration potential to groundwater. The key value of Koc at 20 deg C is equivalent to 548.08 (log Koc :2.7388 )

Henry's Law Constant :

Henry's Law states that at a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.

Henry's Law Constant of phthalylsulfathiazole was estimated to be 0.0000000000000000766017 Pa m³/mol at 25 deg C.