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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Hydrolysis:
The study does not need to be conducted because the substance is readily biodegradable.

Biodegradation in water:

The test chemical piperazine 2-hydroxypropane-1,2,3-tricarboxylate (3:2) (salt) was estimated to be not readily biodegradable in water, by QSAR toolbox.

Bioaccumulation: aquatic / sediment

Bioaccumulation concentration factor (BCF) for Piperazine Citrate is 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000. Thus it is concluded that Piperazine Citrate is not expected to bioaccumulate in the food chain because it does not exceed the BCF criteria.

Adsorption / desorption:

The Soil Adsorption Coefficient i.e Koc value of Piperazine Citrate was estimated using EPI suite KOCWIN Program (v2.00) program as Koc 16.3 L/kg (log Koc is 1.212) at 25 deg.C. This Koc value indicates that the substance Piperazine Citrate has a Negligible sorption to soil and sediment

along with rapid migration potential to groundwater.


Additional information

Hydrolysis:
The study does not need to be conducted because the substance is readily biodegradable.

Biodegradation in water:

Predicted data for the test compound Piperazine citrate(CAS No. 144-29-6) and the study for its read across substance were reviewed for the biodegradation end point and is presented below as weight of evidence approach:

In key study, Biodegradability of 2-hydroxypropane-1,2,3-tricarboxylate (3:2) (salt) (CAS no. 144 -29 -6) is predicted using OECD QSAR toolbox version 3.3 (2018) with log Kow as the primary descriptor. Test substance is estimated to undergo 79.422% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 2-hydroxypropane-1,2,3-tricarboxylate (3:2) (salt) was estimated to be not readily biodegradable in water.

Supporting above prediction, Estimation Programs Interface Suite (EPI suite, 2016) was run to predict the biodegradation potential of the test compound Piperazine citrate (CAS no. 144 -29 -6) 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 Piperazine citrate is expected to be readily biodegradable.

Further, Biodegradation study was conducted according to OECD TG 301 C guideline for evaluating the percentage biodegradability of read across substance Piperazine (Kondo, M. et. al; 1988). Initial test substance conc. used in the study was 20 mg/l. Namely, a water, acetone or DMSO solution (0.1 ml) of the test chemicals was added to a mixture of river/sea water (4.9 ml) from an unpolluted area and an autoclaved solution (5.0ml) of 0.2% peptone in a sterile test tube with a tight plug. After sealed with film and fixed at an angle of 30°in a dark box, the test tubes were incubated at 30°C and shaked at 120rpm. Inoculum used for the study was mixed culture obtained from different sources (Sea water from Tama river and River water from Enoshima Beach). The percentage degradation of test substance was found to be 20% and 77% in 3 days, respectively. Thus, the substance Piperazine was determined to be readily biodegradable in nature.

 

On the basis of above results for target as well as read across substance and by applying weight of evidence approach, it can be concluded that the test substancePiperazine citratecan be expected to be readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

Estimation Programs Interface Suite (EPI suite, 2016) was run to predict the bioconcentration potential of the test compound Piperazine citrate (CAS no. 144 -29 -6). The BCF of the substance was calculated using BCFBAF Program (v3.01) software. Bioaccumulation concentration factor (BCF) for Piperazine Citrate is 3.162 L/kg wet-wt which does not exceed the bioconcentration threshold of 2000. Thus it is concluded that Piperazine Citrate is not expected to bioaccumulate in the food chain because it does not exceed the BCF criteria.

Adsorption / desorption:

Predicted data of adsorption endpoint for the target chemical Piperazine citrate (Cas no. 144-29-6) and studies fro its read across chemical were reviewed and are presented as weight of evidence approach below:  

In key study, the Soil Adsorption Coefficient i.e Koc value of Piperazine Citrate was estimated using EPI suite KOCWIN Program (v2.00) program as Koc 16.3 L/kg (log Koc is 1.212) at 25 deg.C (EPI Suite, 2016). This Koc value indicates that the substance Piperazine Citrate has a Negligible sorption to soil and sedimentalong with rapid migration potential to groundwater.

From predicted model Danish (Q)SAR data base (database developed by the National Food Institute, Technical University of Denmark, with support from the Danish Environmental Protection Agency, the Nordic Council of Ministers and the European Chemicals Agency) indicate that the soil adsorption coefficient (Koc) value of Piperazine citrate is estimated to be 20.55/kg (log Koc =1.3128), indicating that it is has a Negligible sorption to soil and sediment and therefore have rapid migration potential to groundwater.

And read across Piperazine (Cas no. 110-85-0) experimental study from HSDB database;2016 indicate that the adsorption coefficient (Koc) of substance Piperazine was found to be 3.6 using a log Kow of 1.50 and a regression derived equation. This Koc value suggests that piperazine is expected to have very high mobility in soil.

Other study from European Union Risk Assessment Report – PIPERAZINE, 3rd Priority List Volume: 56; Final Report, 2005 for same read across (Cas no. 110-85-0) indicate that adsorption study which is performed with three different soils (loam, sand and sandy loam) using the batch equilibrium method (OECD Guidelines 106) (Geurts, 2003). The optimal soil solution ratio of 1:5 was used for the final sorption test. Equilibrium was reached after approximately 8 hours. During experiment the Kdvalues was found to be 7.9-20. This result indicate that sorption of piperazine to soil is not correlated to the organic carbon content of the soils. Thus study finally concluded that the not to adsorb to or partition into solids to any significant extent, but remained in the water phase.

Thus based on the above all studies and by applying weight of evidence approach it is concluded that the test substance Piperazine citrate (Cas no. 144-29-6) have Negligible sorption to soil/sediment means not adsorb in soil compartment thus very high mobility in soil.

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