Zeolite, cuboidal, crystalline, synthetic, non-fibrous

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 22, 1991 - Oct. 7, 1992; experimental phase: Jun. 18 - Nov. 22, 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

1984

Deviations:

not specified

GLP compliance:

yes

Specific details on test material used for the study:

Wessalith P (A Zeolite)
white flocky powder

Analytical monitoring:

no

Remarks:

The actual dosed amounts of test substance in the test suspensions were not determined by Chemical analysis in any of the tests.

Vehicle:

no

Details on test solutions:

The test substance w as poorly soluble. Newly prepared unfiltered test suspensions were homogeneous turbid and after 24 h the aqueous phases were mostly clear but precipitates were observed on the bottom of the test vessels. Even after filtration, the aqueous phases were not completely clear; after 24 h the aqueous phases w ere clear but undissolved material was observed on the bottom of the test vessels.
Both unfiltered and filtered suspensions were tested: The suspensions w ere stirred at 20°C for one hour. Filtering was through a paper filter.

Test organisms (species):

Daphnia magna

Details on test organisms:

Cultured in the laboratory under standard conditions, according to the principles of NPR 6503. The animals were ca. 24 h old at the beginning of the test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Test temperature:

20 +/- 1 °C

pH:

7.9-10.5

In the “PH test” the pH values appeared not to be stable during the 48 hours of the test period. Because the pH values in the Wessalith P suspensions were more stable it is difficult to comparet the results of both tests. Nevertheless it is very likely that the high pH values attributed adversely to the observed effects.
A “PH test” with DSWL adjusted to various pH values to check the influence of the pH on the test results. The pH of DSWL was adjusted to 9.0, 9.5, 10.0, 10.5 and 11.0 with 2 M NaOH

Dissolved oxygen:

7.0-8.1 mg/l

Nominal and measured concentrations:

1st test: 56, 100, 180, 320, 560, 1,000 and 10,000 mg/l
2nd test: 1,000 and 10,000 mg/l
3rd test: 1,000, 1,800, 3,200, 5,600 and 10,000 mg/l

Details on test conditions:

The tests were carried out under a 16 h light-8 h dark regime with transition periods of 30 minutes.

Reference substance (positive control):

no

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

2 808 mg/L

Nominal / measured:

nominal

Basis for effect:

mobility

Remarks on result:

other: confidence interval: 2,468-3,195 mg/l

Key result

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

5 600 mg/L

Nominal / measured:

nominal

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

1 800 mg/L

Nominal / measured:

nominal

Basis for effect:

mobility

Remarks on result:

other: = 96 h LC0

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Basis for effect:

other: condition

Details on results:

These are the results of the third test with Wessalith P.
The EC50 values and their confidence interval were calculated by means of a parametric model developed by Kooijman.
The NOEC values were estimated by comparing effects with regard to mobility and condition, according to the definition given in the OECD Guideline no. 202.
There were no immobile animals in the control media in any of the tests.

Validity criteria fulfilled:

yes

Conclusions:

The 24h EC50 based on mobility was 2,808 mg/l (confidence interval 2,468-3,195 mg/l), the 24h NOEC based on mobility was 1,800 mg/l.

Executive summary:

The acute toxicity of Wessalith P to the fresh-water crustacean Duphnia magna was determined as described in the OECD Guideline no. 202 and according to the OECD principles of Good Laboratory Practice.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

other: EPA-660/3-75-009 for shrimps

Version / remarks:

1975

Deviations:

not specified

Principles of method if other than guideline:

Butler et al. (1960) and Butler (USHEW 1965) for oysters

GLP compliance:

not specified

Specific details on test material used for the study:

Type-A zeolite

Analytical monitoring:

yes

Details on sampling:

Actual test concentrations of zeolite were measured during all partial and full chronic studies with macroinvertebrates and fish by digesting the aluminosilicate to molybdate-reactive silica after APHA.

Details on test solutions:

The unexchanged sodium form of zeolite was used during all marine tests since the abundance of metal ions in ambient seawater greatly exceeds the complexing capacity of zeolite to significantly alter these metal concentrations.

Test organisms (species):

other: Crassostrea virginica, Penaeus duorarum

Details on test organisms:

Eastern oysters, Crassostrea virginica, 20-30 mm umbo-distal valve edge; and pink shrimp, Penaeus duorarum, 30-45 mm rostrumtelson length, were collected from Big Lagoon, Pensacola, Fla. All test animals were acclimated to laboratory test conditions in natural seawater (salinity of 24%o and pH 8.0 ± 0.5) for a minimum of seven days prior to testing.

Test type:

static

Water media type:

saltwater

Total exposure duration:

96 h

pH:

8.0 +/- 0.5

Salinity:

2.4 %

Nominal and measured concentrations:

780 mg/l

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 780 mg/L

Nominal / measured:

not specified

Basis for effect:

mortality

Remarks on result:

other: shrimp

Duration:

96 h

Dose descriptor:

EC0

Effect conc.:

>= 780 mg/L

Nominal / measured:

not specified

Basis for effect:

morphology

Remarks:

shell deposition

Remarks on result:

other: oysters

Details on results:

The growth of eastern oysters, Crassostrea virginica, as measured by new shell deposition, was not affected in concentrations of Type-A zeolite up to 780 mg/L in flowing seawater. In fact, oysters from the 780-mg/L test concentration had slightly more new shell growth than did the controls. Pink shrimp, Penaeus duorarum, also exhibited no mortality in test concentrations of Type-A zeolite up to 780 mg/L. After 96 h of exposure to the test material, continuously stirred in static seawater with aeration, there were no deaths in any test concentration or control.

Validity criteria fulfilled:

not specified

Conclusions:

The growth of eastern oysters, Crassostrea virginica, as measured by new shell deposition, was not affected in concentrations of Type-A zeolite up to 780 mg/L in flowing seawater. Pink shrimp, Penaeus duorarum, also exhibited no mortality in test concentrations of Type-A zeolite up to 780 mg/L. After 96 h of exposure to the test material, continuously stirred in static seawater with aeration, there were no deaths in any test concentration or control.

Executive summary:

Oysters and shrimps were exposed to type A zeolite for 96 hours. New shell deposition was assessed in oysters, while mortality was evaluated in shrimps.

Description of key information

Only one EC50 value regarding daphnia immobilisation according to OECD guideline 202 was derived at: The 24h EC50 based on mobility was 2,808 mg/l (confidence interval 2,468-3,195 mg/l).

The growth of eastern oysters, Crassostrea virginica, as measured by new shell deposition, was not affected in concentrations of type A zeolite up to 780 mg/l in flowing seawater. Pink shrimp, Penaeus duorarum, also exhibited no mortality in test concentrations of type-A zeolite up to 780 mg/l. The EC0/LC0 in salt water after 96 hours was equal or greater than 780 mg/l.