Silver iodide

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP status unknown, guideline unknown, limitations in reporting but otherwise acceptable for assessment.

Principles of method if other than guideline:

A guideline was not specified. The test was a 96-hour static renewal test. The US EPA 2002 guideline EPA-821/R-02-012 is referenced during the description of the method, but the text does not state its use unambiguously.

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Analytical monitoring:

yes

Details on sampling:

Samples collected at 0, 48 and 96 hours and immediately acidified. Samples were analysed immediately after each test.

Vehicle:

no

Details on test solutions:

Dechlorinated tap water

Test organisms (species):

Pimephales promelas

Details on test organisms:

< 24 h obtained from Aquatic Biosytems, Fort Collins, CO, USA. Held in University of Miami dechlorinated tap water for 7days prior to testing (reference water) or less dependent on age at time of testing (experimental variable). Various life stages: 1, 4, 7, 27 and 41 days old.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

76 mg/L CaCO3

Test temperature:

26ºC

pH:

7.74

Dissolved oxygen:

No data reported

Salinity:

Not applicable

Nominal and measured concentrations:

6 to 7 concentrations - unspecified

Details on test conditions:

Three replicates, ten fish added to each replicate. 1,000 mL plastic beaker containing 500 mL test solution, test solutions renewed at 48 hours (fed Artemia nauplii before solution renewal at 48 hours). Different ages of fish were assessed, ranging from 1-4 days to 41 days at start of test.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.2 µg/L

Nominal / measured:

not specified

Conc. based on:

dissolved

Remarks:

silver

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI 0.72 - 2.07 µg dissolved Ag/L. Fish aged 1-4 day at start of test.

Details on results:

Other LC50 values: 3.37 (7 d old), 5.9 (27 d old), 10.4 (41 d old) µg/L dissolved Ag.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Trimmed Spearman Karber analysis was used to estimate 48- and 96-h LC50s.

Validity criteria fulfilled:

not applicable

Conclusions:

The 96 hour LC50 for fish aged 1-4 days was 1.2 µg dissolved Ag/L. Other LC50 values were: 3.37 (7 d old), 5.9 (27 d old), 10.4 (41 d old) µg dissolved Ag/L. Silver toxicity varied with age and size of P. promelas. As fish aged and mass increased, 96 hour LC50 values increased (organism sensitivity decreased).

Executive summary:

The toxicity of silver toP. promelaswas assessed in a flow through test. For fish aged 1 -4 days, the 96 hour LC50 is 1.5 µg/L dissolved Ag. Other LC50 values were: 3.37 (7 d old), 5.9 (27 d old), 10.4 (41 d old) µg dissolved Ag/L. Silver toxicity varied with age and size of fish. As fish aged and mass increased 96 h LC50 values increased (organism sensitivity decreased). The GLP status of this study is unknown and it is unclear which guideline was followed. However, there is sufficient information for an assessment to be made and the study is considered suitable for use for this endpoint.

Description of key information

The most sensitive data reported is a 96 hour LC50 of 1.2 μg Ag/L for Pimephales promelas (Bielmeyer et al. 2007).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

1.2 µg/L

Marine water fish

Marine water fish

Dose descriptor:

LC50

Effect concentration:

331 µg/L

Additional information

The most sensitive 96-hour LC50 is reported by Bielmeyer et al. (2007) for fathead minnow. Similar LC50 values are reported by other authors (e.g. Karen et al. 1999).

Data on the toxicity of silver to marine fish are more limited. However, the data indicate that marine fish are considerably less sensitive to silver than freshwater species. The most sensitive 96-hour LC50 for marine fish is 331 μg Ag/L for Oligocottus maculosus (Shaw et al. 1988).