Guanidinium nitrate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Remarks:

cell multiplication of bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

9 - 16/06/1988

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:

equivalent or similar to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Deviations:

yes

Remarks:

refer to "principles of method if other than guideline"

Principles of method if other than guideline:

Method: other: acute bacteria cell multiplication inhibition test
deviations from guideline DIN 38412, part 8: - duration in test 18h (Guideline: 15 - 17h)
- temperature: 25°C (Guideline: 20 - 22°C)
-slightly different composition of the solutions

GLP compliance:

yes

Analytical monitoring:

not specified

Details on test solutions:

2500mg Guanidine Nitrate/L in sterile MilliQ-water (Millipore Corp., Bedford, Mass., USA)
pH adjusted to 6.9 with 0.01M NaOH

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: Pseudomonas putida, obtained from RIVM, Bilthoven, The Netherlands
- Method of cultivation: at 25°C
- Preparation of inoculum for exposure: small amounts of bacteria from a 7-day old stock culture inoculated in fluid nutrient medium in erlenmeyer falsks, turbidity measured at 436nm for a 10mm layer, final turbidity adjusted bymeans of sterile saline that dilution 1 + 9 with saline corresponded with extinction value of a Formazin standard supsension TU/F/436nm=10, these preliminary clutures used for inoculation of the test flasks

Test type:

static

Water media type:

freshwater

Total exposure duration:

18 h

Test temperature:

25°C

pH:

6.9

Nominal and measured concentrations:

nominal concentrations:
first experiment: 0.2, 0.6, 2.4, 9.8, 19.5, 39.2, 78.2, 156.3, 625.0, 2500.0, 10000.0, 40000.0, 160000.0 mg/L
second experiment: 1.2, 2.4, 4.9, 9.8, 19.5, 39.1, 78.1, 156.3, 312.5, 625.0, 1250.0, 2500.0mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 300ml Erlenmeyer flasks stoppered with aluminium caps
- Material, size, headspace, fill volume: glas, 300ml, 100ml
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 10
- Biomass loading rate: 10ml of prepared bacterial suspension (TU/F/436nm=10) in 80ml diluted test substance solution, 5ml stock solution I, 5ml stock solution II

Reference substance (positive control):

yes

Remarks:

Methanol (Merck no.6008, The Netherlands)

Key result

Duration:

18 h

Dose descriptor:

EC10

Effect conc.:

831.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Results with reference substance (positive control):

- Relevant effect levels: TT value 7904 and 20108 mg/L

Validity criteria fulfilled:

yes

Conclusions:

The toxicity of Guanidine Nitrate against microorganisms was studied in a cell multiplication inhibition test using Pseudomonas putida as test organism. A toxicity value (TT) of 831.8mg/L was determined.

Executive summary:

In a 16h acute toxicity study, the cultures of the microorganism Pseudomonas putida were exposed to Guanidine Nitrate at nominal concentrations of 0.2, 0.6, 2.4, 9.8, 19.5, 39.2, 78.2, 156.3, 625.0, 2500.0, 10000.0, 40000.0, 160000.0 mg/L in the first, and 1.2, 2.4, 4.9, 9.8, 19.5, 39.1, 78.1, 156.3, 312.5, 625.0, 1250.0, 2500.0mg/L in the second experiment, respectively under static conditions in accordance with the guideline of Umweltbundesamt (1979) and slightly modified to DEV DIN 38412 part8 (1991). Bacterial growth was determined by measurement of the turbidity at 436nm.

The study is in accordance with standard guidelines with some restrictions.

 

Results Synopsis

 

Test organism: Pseudomonas putida

Test Type: static

18-h-EC₁₀:  831.8 mg a.i./L                        

Endpoint(s) Effected: toxicity to microorganisms, growth inhibition

Description of key information

The toxicity of Guanidine Nitrate against bacteria was monitored in different studies.

A 18-h-EC10 of 831.8mg/L was determined.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

831.8 mg/L

Additional information

The toxicity of Guanidine Nitrate to microorganisms was studied in a 18-h-cell multiplication inhibition test using Pseudomonas putida as test organism. Bacterial growth inhibtion was determined by measurement of the turbidity of the bacterial culture. The 18-h-EC10 was 831.8mg/L.