Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
activated sludge nitrification inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data is from authoritative database
Justification for type of information:
Data is from authoritative database
Qualifier:
according to
Guideline:
other: Refer below principle
Principles of method if other than guideline:
To evaluate Toxicity of test material Sodium 1-Naphthalenesulfonate on microorganism
GLP compliance:
not specified
Specific details on test material used for the study:
IUPAC: Sodium 1-Naphthalenesulfonate
Mol. formula: C10H7NaO3S
Molecular Weight:230.218
InChI:1S/C10H8O3S.Na/c11-14(12,13)10-7-3-5-8-4-1-2-6-9(8)10;/h1-7H,(H,11,12,13);/q;+1/p-1
Smiles:c12c(S(=O)(=O)[O-])cccc1cccc2.[Na+]
Details on test solutions:
water solution of test material and AS mixed before experiment and aerated for 10 min
Test organisms (species):
activated sludge
Details on inoculum:
Source: pilot activated sludge plant at Water Research Center, Swindon, UK
Test type:
static
Water media type:
freshwater
Limit test:
no
pH:
7.0 - 8.0
Nominal and measured concentrations:
50 - 200 mg/l
Details on test conditions:
-in vitro; samples of actively-nitrifying sludge mixed liquor, suspended solids, SS in concentration 2000 mg/l; standard procedure for assessment of nitrification inhibition, respiration rate of AS determined from the rate of O2 depletion measured by oxygen electrode
Reference substance (positive control):
not specified
Dose descriptor:
IC50
Effect conc.:
926 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of nitrification rate
Remarks on result:
other: slightly inhibited nitrification
Dose descriptor:
other: IC20
Effect conc.:
195 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of nitrification rate
Remarks on result:
other: no other details available
Validity criteria fulfilled:
not specified
Conclusions:
The inhibition concentration (IC50) for the nitrifying bacteria was observed to be 926 mg/l
Executive summary:

Toxicity of microorganism was evaluated for the test material Sodium 1-Naphthalenesulfonate . Water solution of test material and AS mixed before experiment and aerated for 10 min. Activated sludge having nitrifying bacteria were used obtained from a pilot activated sludge plant at Water Research Center, Swindon. In vitro; samples of actively-nitrifying sludge mixed liquor, suspended solids, SS in concentration 2000 mg/l; standard procedure for assessment of nitrification inhibition,  respiration rate of AS determined from the rate of O2 depletion measured by oxygen electrode. The nominal concentrations tested were 50 - 200 mg/l. The inhibition concentration (IC50) for the nitrifying bacteria was observed to be 926 mg/l , the (IC20) was observed to be 195 mg/l. Slightly inhibited nitrification was observed.

Description of key information

Toxicity to microorganism:

Toxicity of microorganism was evaluated for the test material Sodium 1-Naphthalenesulfonate . Water solution of test material and AS mixed before experiment and aerated for 10 min. Activated sludge having nitrifying bacteria were used obtained from a pilot activated sludge plant at Water Research Center, Swindon. In vitro; samples of actively-nitrifying sludge mixed liquor, suspended solids, SS in concentration 2000 mg/l; standard procedure for assessment of nitrification inhibition,  respiration rate of AS determined from the rate of O2 depletion measured by oxygen electrode. The nominal concentrations tested were 50 - 200 mg/l. The inhibition concentration (IC50) for the nitrifying bacteria was observed to be 926 mg/l , the (IC20) was observed to be 195 mg/l. Slightly inhibited nitrification was observed.

Key value for chemical safety assessment

EC50 for microorganisms:
926 mg/L

Additional information

Toxicity to microorganism:

Toxicity of microorganism was evaluated for the test material Sodium 1-Naphthalenesulfonate . Water solution of test material and AS mixed before experiment and aerated for 10 min. Activated sludge having nitrifying bacteria were used obtained from a pilot activated sludge plant at Water Research Center, Swindon. In vitro; samples of actively-nitrifying sludge mixed liquor, suspended solids, SS in concentration 2000 mg/l; standard procedure for assessment of nitrification inhibition,  respiration rate of AS determined from the rate of O2 depletion measured by oxygen electrode. The nominal concentrations tested were 50 - 200 mg/l. The inhibition concentration (IC50) for the nitrifying bacteria was observed to be 926 mg/l , the (IC20) was observed to be 195 mg/l. Slightly inhibited nitrification was observed.