(3-chloro-2-hydroxypropyl)trimethylammonium chloride

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2005-06-15 to 2006-10-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: OECD 303A

Principles of method if other than guideline:

The adsorption coefficient was determined by analytical measurment of test substance concentrations in water and sludge on six test days during the course of an OECD 303A simulation study.

GLP compliance:

yes (incl. QA statement)

Type of method:

other: Adsorption to sludge measured during OECD 303A simulation study

Media:

sewage sludge

Radiolabelling:

no

Test temperature:

20 ± 2 °C

Analytical monitoring:

yes

Details on sampling:

Samples of water and sludge were taken for analysis on days 57, 61, 64, 111, 112 and 113 of the test.

Details on matrix:

Test matrix was sewage effluent and sludge from an OECD 303A simulation study.

Computational methods:

Kpsludge = conc. in sludge/conc. in water
Although the organic carbon content of the sludge was not measured during the test, it has been assumed that the proportion of the organic carbon in sludge is 50 %.

Type:

Koc

Value:

68.8 L/kg

Temp.:

20 °C

% Org. carbon:

ca. 50

Validity criteria fulfilled:

not applicable

Conclusions:

As part of an OECD 303A degradation simulation study, measured concentrations of CHPTAC in sludge and water were used to determine the Koc based on an assumed organic carbon content of 50 %. The measured Kp sludge was 34.4 kg/l, equivalent to Koc = 68.8 l/kg.

Reference 2

Endpoint:

adsorption / desorption

Remarks:

adsorption

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

The study was conducted according to an appropiate (draft) OECD Test Guideline and in compliance with GLP. Full details of the analytical method used were not reported.

Qualifier:

according to guideline

Guideline:

other: ISO/CD 18749, "Water quality - Adsorption of substances on activated sludge- Batch test using specific analytical methods" Draft Guideline 2002

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

sewage sludge

Radiolabelling:

no

Test temperature:

21-24°C

Analytical monitoring:

yes

Sample No.:

#1

Duration:

72 h

Initial conc. measured:

126.2 other: m/l

pH:

7

Sample No.:

#2

Duration:

72 h

Initial conc. measured:

127.2 other: mg/l

pH:

7

Validity criteria fulfilled:

yes

Conclusions:

In a 72 h test carried out in accordance with ISO 18749 draft test guideline, the removal of CHPTAC from water was 22 %. However, removals in the abiotic control (without the sludge) and sterile control (with sterile sludge) were almost the same, 22 % and 27 % respectively. As the concentration of CHPTAC in the sludge was not measured at the end of test it is not possible to estimate the partition coefficient (Kd) to sludge.

Description of key information

As part of an OECD 303A degradation simulation study, measured concentrations of CHPTAC in sludge and water were used to determine the Koc based on an assumed organic carbon content of 50 %. The measured Kp sludge was 34.4 kg/l, equivalent to Koc = 68.8 kg/l.

Key value for chemical safety assessment

Koc at 20 °C:

68.8

Other adsorption coefficients

Type:

log Kp (solids-water in activated sewage sludge)

Value in L/kg:

1.54

at the temperature of:

20 °C