Reaction products of sodium glucoheptonate with copper sulfate and ammonium hydroxide

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:

weight of evidence

Study period:

1961

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Two series of tests with ten rainbow trouts were made, one in a hard unchlorinated borehole water (total hardness 320 mg./l. as CaC03) and the other in an artificial soft water (total hardness 15-20 mg./l. as CaCO3). Copper was added to the solutions as sulphate. The median lethal concentration after 3 and 7 days was determined.

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

not specified

Details on test solutions:

Two series of tests were made, one in a hard unchlorinated borehole water (total hardness 320 mg./l. as CaCO3) and the other in an artificial soft water (total hardness 15-20 mg/L as CaCO3) prepared by diluting the borehole water with demineralized water and adding 15 mg/L sodium chloride to the final solution. Both zinc and copper were added to the solutions as sulphates; the ratio of zinc to copper (as mg/L) used in the solutions containing both metals was 6:1.

Test organisms (species):

other: Salmo gairdnerii Richards

Details on test organisms:

Ten rainbow trout (about 3 in. long) were used in each test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 d

Hardness:

320 mg/L as CaCO3, 15 - 20 mg/L as CaCO3

Test temperature:

15.5 - 17 °C, 17 - 18 °C

Details on test conditions:

Tests were conducted in 40 L volumes of solution, aerated with a controlled mixture of air and carbon dioxide to give a concentration of about 8 mg/L free carbon dioxide in solution; ten rainbow trout (about 3 in. long) were used in each test. The sequence of tests, and the distribution of the fish between the test aquaria, were randomized in both the hard- and soft-water series. Rainbow trout to be used in the hard-water series were acclimatized to room temperature (15.5 - 17 °C.) and free carbon dioxide concentration for 1 day before the test; those used in the soft-water series had previously been living in hard water and were acclimatized to the dilution water and room temperature ( 17.0 - 18.0 °C.) for 5 days, with acclimatization to free carbon dioxide concentration on the last day. Survival times were measured from the time of immersion to the time when all respiratory movement ceased; distributions of survival times were logarithmic normal and median periods of survival were estimated graphically (Bliss, 1937). Fish which survived for more than 24 h were transferred to fresh solutions daily and were fed on alternate days.

Reference substance (positive control):

no

Duration:

3 d

Dose descriptor:

other: median period of survival

Effect conc.:

1.1 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

mortality (fish)

Remarks on result:

other:

Remarks:

hard water

Duration:

7 d

Dose descriptor:

other: median period of survival

Effect conc.:

0.044 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

mortality (fish)

Remarks on result:

other:

Remarks:

soft water

Details on results:

Under the conditions of the experiments in hard water, the concentration of copper which gave median periods of survival equal to the duration of the experiment (3 days) was 1.1 mg/L Cu, in soft water the value of and Cu was 0.044 mg/L for a 7-day median period of survival.

Conclusions:

This study demonstrates that the hardness of water has a significant impact on copper toxicity. While in soft water (15 - 20 mg/L as CaCO3) the copper concentration giving a median period of survival was 0.044 mg/L in a total exposure time of 7 days, the copper concentration giving a median period of survival in hard water (320 mg/L as CaCO3) was 1.1 mg/L copper in a total exposure time of 3 days.

Executive summary:

This study demonstrates that the hardness of water has a significant impact on copper toxicity. While in soft water (15 - 20 mg/L as CaCO3) the copper concentration giving a median period of survival was 0.044 mg/L in a total exposure time of 7 days, the copper concentration giving a median period of survival  in hard water (320 mg/L as CaCO3) was 1.1 mg/L copper  in a total exposure time of 3 days.

Description of key information

It was demonstrated that the hardness of water has a significant impact on copper toxicity for rainbow trouts. While in soft water (15 - 20 mg/L as CaCO3) the copper concentration giving a median period of survival was 0.044 mg/L in a total exposure time of 7 days, the copper concentration giving a median period of survival  in hard water (320 mg/L as CaCO3) was 1.1 mg/L copper  in a total exposure time of 3 days (Lloyd, 1961).

Additional information

The median period of survival converted to copper Glucoheptonate is 322.1 µg Cu GHA/L in a total exposure time of 7 days in soft water (15 - 20 mg/L as CaCO3) and 8057.1 µg Cu GHA/L in a total exposure time of 3 days in hard water (320 mg/L as CaCO3).