Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
02/1984-11/1984
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:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Principles of method if other than guideline:
guideline was not mentioned in the study, but the method was carried out as described in the guideline OECD 202.
GLP compliance:
not specified
Analytical monitoring:
yes
Details on test solutions:
made from dilutions of stock solutions of Guanidine nitrate dissolved in well water
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Source: from in house culture
- Age at study initiation (mean and range, SD): less than 24hours, all non-adult daphnias removed from the stock tanks less than 24hours prior to start of the test, neonates obtained from 27day-old daphnias
- Feeding during test
- Food type: Ankistrodesmus falcatus raised and supplemented with vitamins as recommended by Goulden etal., 1982
-Amount: 2mg/L (dry weight) in the morning, 4mg/L (dry weight) in the afternoon
- Frequency: fed twice each day


Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Hardness:
197mg/L CaCO3
Test temperature:
19.4-20.6
pH:
8.5-8.7
Dissolved oxygen:
8.3-9.0mg/L, 80% saturation
Nominal and measured concentrations:
nominal: 100, 60, 36, 21.6, 13.0, 0 mg/L of the test item
measured: 97.5, 58.5, 40.5, 25.0, 14.5, <0.5mg/L of the test item
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 250ml borosilicate beakers, 200ml of test solution
- No. of organisms per vessel:10
- No. of vessels per concentration (replicates):3
- No. of vessels per control (replicates): 3


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: from 62m well at Ft. Detrick, water softening system, afterwards pumped through a spray nozzle for aeration and sent through a 5micron cellulose acetate cartidge filter, an UV sterilizer, and temperature control equipment prior to use in test
- Conductivity:868micro mhos/cm

OTHER TEST CONDITIONS
- Photoperiod:16h light 8 h dark (Durotest Optima 50bulbs, Color Rendering Index 91)
- Light intensity: 400lux (test), 200lux (stock)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
after 24 and 48hours
Reference substance (positive control):
not specified
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
70.2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 66.0 to 74.7

nominal GN concentration (mg/L)

Mean measured GN concentrationA

(mg/L)

%ImmobilizationB

24h

48h

100

97.5

6.7(33.3)C

100(-)

60

58.5

0(10.0)

13.3(3.3)

36

40.5

0(26.7)

3.3(16.7)

21.6

25.0

0(13.3)

0(6.7)

13.0

14.5

0(20.0)

0(3.3)

0 (control)

<0.5D

0(0)

0(0)

AMean of two measurements

B% of 30daphnids exposed at each treatment level

C% of daphnids caught in surface film

Dbelow detection level

Validity criteria fulfilled:
yes
Conclusions:
The 48–hr-acute toxicity of Guanidine Nitrate to Daphnia magna was studied under static conditions.  Daphnids were exposed to control and test chemical at nominal concentrations of 13.0, 21.6, 36, 60, and 100mg/L for 48 hr.  Immobilization was observed at test termination after 48h and additionally after 24hours. 48-h-EC50 was 70.2mg/L .  
Executive summary:

The 48–hr-acute toxicity of Guanidine Nitrate to Daphnia magna was studied under static conditions.  Daphnids were exposed to control and test chemical at nominal concentrations of 13.0, 21.6, 36, 60, and 100mg/L for 48 hr.  Immobilization was observed at test termination after 48h and additionally after 24hours. 48 -h-EC50 was 70.2mg/L .  

 This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

 

Test Organism Age: neonates from 27day old daphnids obtained less than 24h before testing

Test Type: static 

48-h-EC50:  70.2mg a.i./L                       95% C.I.:  66.0 to 74.7 mg a.i./L

Endpoint(s) Effected:  short term toxicity to aquatic invertebrates

Description of key information

The 48hr-acute toxicity of the read-across substance Guanidine Nitrate to aquatic invertebrates was studied.

The immobilization of Daphnids was used as the critical criteria. A 48-h-EC50 of 70.2mg/L was found.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
70.2 mg/L

Additional information

The study of the acute toxicity of the read-across substance Guanidine Nitrate against Daphnia magna in the report of van der Schalie (1985) shows that the 48 -h-EC50, the concentration, in which 50 per cent reduction in immobilization occurs, is at 70.2mg/L.

Justification for read-across:

Guanidine hydrochloride and guanidine nitrate dissociate in aqueous media to yield the guanidine ion and the respective anion. Therefore it is reasonable to discuss the effects of the ions separately. The chloride ion is a naturally occurring essential ion in human beings with well-known metabolism and mechanisms of action as described in standard textbooks on pharmacology and physiology. As well it is found as salt in the Earth´s crust and is dissolved in seawater. Effects of guanidine hydrochloride are expected to be based primarily on the guanidine ion. The physiological processing of the guanidine ion is expected to be independent of the individual source. Therefore read-across from guanidine nitrate for effects of guanidine dissociated from guanidine hydrochloride is considered valid. This strategy is supported by a quite similar toxicological profile of both substances, as shown in acute toxicity, irritation, sensitization and genotoxic studies.

A more detailed justification for read-across is attached in IUCLID chapter 13.