Reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide

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

Study period:

1991-04-08 to 1991-06-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP, Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted April 4, 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

adopted September, 1984

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all tested concentrations
- Sampling method: Samples were taken from all dose groups in duplicate at the start (t = 0 h) and at the end of the test (t = 96 h). The samples were shipped to RCC Umweltchemie at the day of sampling and arrived there the next day. Shipment was done at ambient temperature.
- Sample storage conditions before analysis: Samples were worked off upon arrival.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- The test media were prepared using stock solutions in DWS (Dutch standard water). For this purpose the test substance was added quantitatively providing concentrations of 1000 or 2000 mg/L. Ultra sonication was applied to accelerate the dissolving of the test substance. The final test solutions ranged from clear to turbid without substance deposits at the start of the exposure. The concentrations of the test item actually prepared were: 97, 174, 309, 541, and 1010 mg/L.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: Carp (Cyprinus carpio, Teleostei, Cyprinidae (Linnaeus, 1758))
- Source: Zodiac, proefacc, "De Haar Vissen", L.U. Wageningen, The Netherlands
- Age at study initiation (mean and range, SD): no data
- Length at study initiation (length definition, mean, range and SD): 2.3 +/- 0.15 cm
- Weight at study initiation (mean and range, SD): 0.25 +/- 0.04 g
- Method of breeding: Pathogen-Free F1 from a single parent-pair
- Feeding during test: no feeding from 24 hours prior to the test and during the total test period

ACCLIMATION
- Acclimation period: at least 14 days after delivery
- Acclimation conditions (same as test or not): Following a 48-hour settling-in period the fish were allowed to acclimatise to the test medium without test substance for at least seven days.
- Type and amount of food: Trouvit or Artemia
- Feeding frequency: daily until 24 hours prior to test
- Health during acclimation (any mortality observed): In the batch of fish used for the test, mortality during the seven days prior to the start of the test was less than 5 %.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

210 mg CaCO3/L

Test temperature:

20.5 to 22.5 °C

pH:

7.8 to 8.4

Dissolved oxygen:

> 5 mg/L for all measurements performed during the final study

Salinity:

The test medium DWS had the following ion composition:
- Ca2+: 54.4 mg/L
- Mg2+: 17.5 mg/L
- Na+: 27.4 mg/L
- K+: 7.8 mg/L
Cl-: 96.6 mg/L
SO4(2-): 70.1 mg/L

Nominal and measured concentrations:

nominal: 100, 180, 320, 560, and 1000 mg/L
actually prepared: 97, 174, 309, 541, and 1010 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 5 litres, all-glass
- No. of organisms per vessel: 10
- No. of vessels per concentration: 1
- No. of vessels per control: 1
- Biomass loading rate: 0.6 g fish/litre, i.e. 10 fish per 4 litres of test medium
- Introduction of fish: Directly after preparation of the test media fish were introduced into the test medium, provided that the temperature of the medium was within the optimal range.
- Illumination: 16 hours photoperiod daily

EFFECT PARAMETERS MEASURED:
- Mortality and other effects: At 2.5, 24, 48, 72, and 96 hours following the start of exposure. Fish were considered to be dead when no reaction was observed after touching the caudal peduncle and visible breathing movements were absent.
- Dissolved oxygen content and pH: Daily in all vessels, beginning at the start of the test.
- Temperature of media: Daily in control vessel, beginning at the start of the test.

RANGE FINDING STUDY:
- Test concentrations: Five fish per concentration were exposed to a concentration range of nominally 1 to 1000 mg/L with an increasing factor of 10. The highest concentration (1000 mg/L) was tested unfiltered and filtered.
- Results used to determine the conditions for the definitive study: 100 % mortality of fish was recorded within 24 hours at nominally 1000 mg/L, in both the unfiltered and the filtered solution. No mortality was seen at or below nominally 100 mg/L.

ACCEPTABOILITY OF THE TEST:
- The mortality in the blank control should not exceed 10 %.

Reference substance (positive control):

yes

Remarks:

A reference test with pentachlorphenol (PCP, SIGMA) is carried out every 3 months. The most recent test was performed April, 1991.

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

409 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Remarks:

as representative element for the whole substance, aluminium was measured by AAS

Basis for effect:

mortality (fish)

Remarks on result:

other: 95 % confidence interval: 309 to 541 mg/L

Details on results:

- Mortality: Within 2.5 hours of exposure all fish had died at nominally 541 mg/L and higher. No lethal effects in carp at or below nominally 309 mg/L corresponding with an aluminium concentration of 8.9 mg/L.
- Other effects: No other effects besides mortality were observed.
- LC50: The LC50 value calculated from the data recorded after 2.5 hours following the start of the test was 409 mg/L when based on nominal concentrations of the test item in water. It did not change during the remaining part of the exposure. Therefore, the 96 h-LC50 was nominally 409 mg/L corresponding with an aluminium concentration of 12.4 mg/L. The study authors discussed, that the presence of aluminium-ions is probably the most important factor responsible for the toxicity of the test item. The 95 % confidence interval ranged from 309 to 541 mg/L.
- Analytical control: From 24 hours onwards an increasing amount of substance deposits were seen in all vessels except the control. After 96 hours of exposure no detectable concentrations of dissolved aluminium could be found. This was probably related to the increasing amount of substance deposits formed during the test period possibly due to precipitation of aluminiumhydroxide.
- Mortality of control: In the control no mortality was observed.

Results with reference substance (positive control):

- Results with reference substance valid: yes
- LC50: The 96h-LC50 of the most recent test with the positive control substance pentachlorphenol (tested April, 1991) is 0.24 mg/L with a 95 % confidential interval between 0.18 and 0.32 mg/L. The historical range of the 96h-LC50 for carp recorded in reference tests approximately every 3 months since April 1988 is between 0.18 and 1.0 mg/L.

Executive summary:

In a 96-h acute toxicity study according to OECD Guideline 203, adopted April 4, 1984 and EU method C-1, adopted September, 1984, carp (Cyprinus carpio) were exposed to substance "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" (90 % a.i.) at nominal concentrations of 0 (control), 97, 174, 309, 541, and 1010 mg/L under static conditions. 

The 96-h LC₅₀ was 409 mg/L (95 % confidence interval: 309 to 541 mg/L). The NOEC value was 309 mg/L, based on mortality.

At the next higher tested concentration of 541 mg/L the mortality was 100 %. No other effects besides mortality were observed. 

This toxicity study is classified as acceptable and satisfies the requirements of the OECD guideline 203 and the EU method C-1 (acute toxicity for fish).

 

Description of key information

A reliable, relevant and adequate study according to OECD Guideline 203, adopted April 4, 1984 and EU method C-1, adopted September, 1984 is available.

The 96-h LC50 for carp (Cyprinus carpio) was 409 mg/L (95 % confidence interval: 309 to 541 mg/L).
The dissociation of the substance in water will result in common environmental constituents - calcium, aluminium, phosphate. Calcium and phosphate are essential for almost all living organisms including fresh- and saltwater fish and natural constituents of their habitats. Aluminium as most abundant metallic element of the earth´s crust, is also a natural component in environmental habitats. Therefore, the substance is not expected to have a relevant intrinsic toxic activity to aquatic organisms.
Noticed toxicity is most probably triggered by a pH effect. Dissociation of the reaction mass under the conditions of OECD Guidelines 112 or 105, resulted in a pKa of 10.1 and a pH of 11.4, respectively. A temporary pH effect as toxicodynamic reason for aquatic toxicity of inorganic alkaline substances dissolving in common environmental constituents has been discussed in detail in the EU Risk Assessment on sodium hydroxide and in several OECD HPV SIDS documents on alkaline substances. In general, natural waters do have a sufficient buffering capacity to overcome this effect (c. f. EU RAR sodium hydroxide, 2007; http: //echa. europa. eu/documents/10162/0ded9c53-4082-405b-b09a-e16e57e158af) or e. g. http: //www. inchem. org/documents/sids/sids/Naco. pdf). Therefore, substance "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" is not expected to have a relevant intrinsic toxic activity to aquatic organisms and PNECs will not be derived.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

409 mg/L

Additional information

In a 96-h acute toxicity study according to OECD Guideline 203, adopted April 4, 1984 and EU method C-1, adopted September, 1984, carp (Cyprinus carpio) were exposed to substance "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" (90 % a.i.) at nominal concentrations of 0 (control), 97, 174, 309, 541, and 1010 mg/L under static conditions. 

The 96-h LC₅₀ was 409 mg/L (95 % confidence interval: 309 to 541 mg/L). The NOEC value was 309 mg/L, based on mortality. At the next higher tested concentration of 541 mg/L the mortality was 100 %. No other effects besides mortality were observed.   

This toxicity study is classified as acceptable and satisfies the requirements of the OECD guideline 203 and the EU method C-1 (acute toxicity for fish).