Cetalkonium chloride

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed journal and handbook

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Principles of method if other than guideline:

Biodegradation study was conducted for 25 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test).

GLP compliance:

not specified

Specific details on test material used for the study:

- Other: Test chemical was purchased from Fluka Chem. Corp.
- Purity: ≥ 97%

Oxygen conditions:

not specified

Inoculum or test system:

not specified

Duration of test (contact time):

25 d

Initial conc.:

2.5 mg/L

Based on:

test mat.

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

(%degradation)

Key result

Parameter:

% degradation (test mat. analysis)

Remarks:

and DOC removal

Value:

80

Sampling time:

15 d

Remarks on result:

other: Sampling time: 8 to 15 days, %degradation = approx. 80% at test chemical conc. of 2.5 mg/l.

Key result

Parameter:

% degradation (test mat. analysis)

Remarks:

and DOC removal

Value:

> 50 - < 60

Sampling time:

20 d

Remarks on result:

other: at test chemical conc. of 10 mg/l.

Details on results:

Test chemical undergoes approx. 80 and 50-60% degradation by test material analysis (%degradation) and DOC parameter in 8 to 15 days at conc. of 2.5 mg/l and 20 days at conc. of 10 mg/l, respectively.

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

The percentage degradation of test chemical was determined to be approx. 80 and 50-60% degradation by test material analysis (%degradation) and DOC parameter in 8 to 15 days at conc. of 2.5 mg/l and 20 days at conc. of 10 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in water.

Executive summary:

Biodegradation study was conducted for 25 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test). Test chemical conc. used in the study were 2.5 and 10 mg/l, respectively. For the test chemical, the conventional disulphine- blue active substance test (DBAS test) and the dissolved organic carbon (DOC) disappearance method were used for monitoring their biodegradation. In these tests, the total biodegradation or conversion of the substrate toC02,water and biomass, would result in a decrease of both the DBAS and the organic carbon (DOC) values.The percentage degradation of test chemical was determined to be approx. 80 and 50-60% degradation by test material analysis (%degradation) and DOC parameter in 8 to 15 days at conc. of 2.5 mg/l and 20 days at conc. of 10 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

Description of key information

Biodegradation study was conducted for 25 days for evaluating the percentage biodegradability of test chemical (from peer reviewed journal (J. Sanchez Leal et. al., 1994) and handbook (S. Gangolli, 1999)). The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test). Test chemical conc. used in the study were 2.5 and 10 mg/l, respectively. For the test chemical, the conventional disulphine- blue active substance test (DBAS test) and the dissolved organic carbon (DOC) disappearance method were used for monitoring their biodegradation. In these tests, the total biodegradation or conversion of the substrate toC02,water and biomass, would result in a decrease of both the DBAS and the organic carbon (DOC) values.The percentage degradation of test chemical was determined to be approx. 80 and 50-60% degradation by test material analysis (%degradation) and DOC parameter in 8 to 15 days at conc. of 2.5 mg/l and 20 days at conc. of 10 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Various experimental key and supporting studies of the test chemical were reviewed for the biodegradation end point which are summarized as below:

 

In an experimental key study from peer reviewed journal (J. Sanchez Leal et. al., 1994) and handbook (S. Gangolli, 1999),biodegradation experiment was conducted for 25 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test). Test chemical conc. used in the study were 2.5 and 10 mg/l, respectively. For the test chemical, the conventional disulphine- blue active substance test (DBAS test) and the dissolved organic carbon (DOC) disappearance method were used for monitoring their biodegradation. In these tests, the total biodegradation or conversion of the substrate toC02,water and biomass, would result in a decrease of both the DBAS and the organic carbon (DOC) values.The percentage degradation of test chemical was determined to be approx. 80 and 50-60% degradation by test material analysis (%degradation) and DOC parameter in 8 to 15 days at conc. of 2.5 mg/l and 20 days at conc. of 10 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

In an supporting study from peer reviewed journal (J. Sanchez Leal et. al., 1994), biodegradation experiment was conducted for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 303 A (Simulation test–Aerobic sewage treatment: Coupled unit tests) under aerobic conditions. Test chemical conc. used for the study were 0.5, 1.0, 2.5, 10 and 20 mg/l, respectively. The percentage degradation of test chemical was determined to be 95-100 and > 75% degradation by test material analysis (%degradation) parameter in 7 days at conc. of 10 and 20 mg/l, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature.

 

Another biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test). Test chemical conc. used for the study were 5 and 40 mg/l, respectively. The percentage degradation of test chemical was determined to be ≥ 90 and ≥ 95% degradation by test material analysis (%degradation) parameter after a period of 24 and 48 hrs, respectively. Thus, based on percentage degradation, test chemical is considered to be readily biodegradable in nature

 

In an supporting study, biodegradation study was conducted for 25 days for evaluating the percentage biodegradability of test chemical. The study was performed according to OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test) under aerobic conditions. Test chemical conc. used in the study was 5 mg/l. Test chemical content was analyzed by the DBAS method and primary biodegradation was stated as the percentage of DBAS removal. DOC measurements were periodically performed and ultimate biodegradation was stated as the percentage of DOC removal. Ultimate biodegradation or mineralization was determined by DOC removal. DOC determination involves a sample membrane filtration to remove bacterial cells. To check whether the surfactant removal was really due to its biodegradation, TOC measurements were also carried out. TOC and DOC were determined by the combustion-infrared method using a TOC Analyzer (Shimadzu TOC-5050). For the DOC determinations, samples were subjected to membrane filtration (0.22mm pore size) and decarbonation by acidification with HCl prior to being analyzed by the TOC Analyzer. The percentage degradation of test chemical was determined to be 30 and 0% degradation by test material analysis (%degradation) & DOC parameter in 28 and 20 days, respectively. Thus, based on percentage degradation, test chemical is considered to be primary inherentlybiodegradable in nature.

 

For the target chemical from peer reviewed journal (Garcia et al, 1999), an experiment was performed to determine biodegradability of test chemical in anaerobic condition. The anaerobic sludge and the test chemical were incubated in 250 mL pressure-resistant glass bottles at 35 oC. The bottles were fitted with gas tight septa and aluminium crimp seals. After sealing the vessels and incubating them for about 1 hour at 35oC, excess gas was released to the atmosphere and the incubation proceeded in the dark. The evolved pressure was measured weekly with a digital manometer connected to a syringe needle which was inserted through the septum and excess of biogas was released. The increase in headspace pressure in the closed bottles was used to follow the biodegradation process. At the end of the test, after allowing the sludge to settle, vessels were opened and the dissolved part of carbon dioxide was determined as the concentration of inorganic carbon (IC) in the clear supernatant. For the measurements of inorganic carbon (IQ a carbon analyzer was used (Shimadzu TOC-5050). At the end of the test period, specific analyses of cationic surfactant both in the supematant Liquor and in the settled sludge were carried out to determine the primary biodegradation extent. The analytical procedure included diverse steps of extraction, clean-up and concentration of cationic surfactant [IO] and final quantification by the DBAS method. The biodegradability of test chemical is determined to be 28 % by using anaerobic sludge as inoculums in anaerobic condition and gas production as parameter in 200 days. This percent degradability value in 200 days indicates that test chemical is inherently biodegradable.

 

On the basis of overall results for test chemical (from peer reviewed journals and handbook), it can be concluded that the test chemical can be expected to be readily biodegradable in nature.