Aluminium tris(dihydrogen phosphate)

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target chemical and the source chemical have the same common origin since polyphosphates like aluminium metaphosphate are formed by condensation reactions of aluminium orthophosphates.
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
No additional information
3. ANALOGUE APPROACH JUSTIFICATION
The data submitted is indicative of the toxicity profile of aluminium phosphates in natural environments.
See full read-across justification attached under Section 13 of this dossier and summary of data included in the endpoint summary under Section 6.1 of this dossier.

4. DATA MATRIX
See full read-across justification attached under Section 13 of this dossier and summary of data included in the endpoint summary under Section 6.1 of this dossier.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

yes

Remarks:

pH was not in the range of 6 to 9 on day 0- 3

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Integration und Soziales des Landes Nordrhein-Westfalen

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.096, 0.24, 0.60, 1.50 and 3.75mg/L (nominal test item concentration), fresh and aged test solution. The time weighted mean were calculated. For concentration below the limit of quantification (LOQ) and above the limit of detection (LOD) a value half of the LOQ was set. For concentration below the LOD, the value of the LOD was set.
- Sampling method: Exactly 20 mL of aqueous samples were transferred into disposable 50 mL polyethylene vials, and acidified by addition of 0.2 mL of conc. nitric acid to 20 mL of sample for stabilisation.
- Sample storage conditions before analysis: none

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test solution was prepared by applying the Water Accomodated Fraction (WAF) approach according to the OECD guidance No. 23. WAF was prepared by adding 3.75 mg/L (highest loading) test substance to the test medium. The preparation was strirred for 24 hours at 20°C. Subsequently the solution was filtered using a 0.2 µm filter (PES) bottle top filter. The loading of 0.096, 0.24, 0.60 and 1.50 mg test item/L was prepared with dilution of the filtered clear solution. The test solution was freshly prepared before test start and renewal.
- Differential loading: 0.096, 0.24, 0.60, 1.50 and 3.75 mg test item/L
- Controls: control consists of dilution water only (10 replicates)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: German Federal Environment Agency, Institut für Wasser-, Boden- und Lufthygiene. Specimens used in the test are bred in the laboratory of the Fraunhofer IME
- Age of parental stock (mean and range, SD): 4 – 24 hours old
- Feeding during test: yes
- Food type: a mixture of suspensions of unicellular alga Desmodesmus subspicatus and JBL ArtemioFluid in a ratio of 9 : 1 (vol/vol).
- Amount: The content of food in the test suspensions, measured at 585 nm, is kept constant at 0.2 mg C/Daphnia/day
- Frequency: daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

2.5 - 2.8 mmol/L

Test temperature:

19.7 – 19.9 °C

pH:

7.77 - 10.27

Dissolved oxygen:

7.93 - 9.98 mg/L

Nominal and measured concentrations:

Nominal test substance concentrations: 0.096, 0.24, 0.60, 1.50 and 3.75mg/L

Analytically determined concentrations:
Aluminium concentrations: 0.21, 0.96, 2.87, 7.09 and 18.9 µg Al/L
recalculated test substance concentrations: 1.87, 8.33, 14.9, 61.4, and 164 µg test item/L

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Type (delete if not applicable): covered with panes
- Material, size, headspace, fill volume: Polypropylene, 120 mL nominal, 50 mL fill volume
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): three times weekly
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO test water according to OECD 202

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 hours light/dark cycle
- Light intensity: 15-20 µE / (m2 * s) or 1125 - 1500 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Mobility and any abnormalities in appearance and behaviour were recorded daily. The newborn daphnids per beaker were counted and removed daiky until all daphnids start to reproduce (al least 10 days and at a maximum of 14 days). After that newborn daphnids were counted and removed three times weekly at each water renewal. Any abnormalities in condition (including male sex) or presence of winter eggs were checked and recorded. At study termination, length of the survived adults up to the highest treatment was measured by digital photography and image analysis.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

- Mortality of parent animals: Concentration relating mortality of the adults was not observed.
- No. of offspring produced per day per female: The cumulative number of offspring per replicate ranged from 78 to 86 in the control and at 0.21, 0.96, 2.87, and 7.09 µg Al/L (TWM). At 18.89 µg Al/L the cumulative number of offspring per replicate was 56.
- Body length and weight of parent animals: Adult body length exhibited significant differences between treatments (NOECgrowth 7.09 µg Al/L (TWM)).
- Time to first brood release or time to hatch: Age at the first brood was between 10.2 and 11.0 days up to the highest concentration tested. The difference was not statistically significant.
- Intrinsic rate: The intrinsic rate of increase ranged from 0.288 to 0.307 in the control and up to the highest treatment. The difference was not statistically significant.
- Other biological observations: No other clinical signs were observed in any replicate at any concentration tested. Neither any physical nor pathological symptoms were obtained.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 (24h) = 1.32 mg/L

The test substance has a chronic adverse effect on adult Daphnia magna under the chosen test conditions. Reproduction and growth of the adults was affected. The NOEC_Reproductionand NOEC_Growthis 7.09 µg Al/L (TWM), corresponding to 61.4 µg test item/L (TWM) (1.50 mg test item/L, nominal).

The pH was not in the range within 6 to 9 (guideline). On day 3 in the aged test solution the pH were measured with 10.0 to 10.3. The higher pH was only a short period of time and in all test vessels at all concentrations. The validity criteria of at least 60 juveniles per female was realised. The deviation is assessed to be without influence on the integrity and results of the study. The pH values at all treatment levels were on the other days in fresh and aged solutions 7.8 – 8.4.

The light intensity was measured using an illuminance meter (MINOLTA) with photometric sensor in Lux. With 819 – 862 lx (corresponding to 10.9 – 11.5 µE/(m² *s)) the light intensity was below the threshold value of about 1000 - 1500 lx (15–20 µE/(m² *s)) as permitted by OECD guideline 211. But the light intensity was below the threshold value in all test concentrations.

The validity criteria of at least 60 juveniles per female was realised. Thus, the deviation is assessed to be without influence on the integrity and results of the study.

Concentrations of the test item

(Time weighted mean measured aluminium concentrations [µg Al/L], time weighted mean recalculatedtest item concentrations [µg TI/L], and percentage of nominal concentration [%]. TI = test item)

Nominal conc.	0.096 mg TI/L 11.1 µg Al/L	0.24 mg TI/L 27.7 µg Al/L	0.60 mg TI/L 69.2 µg Al/L	1.50 mg TI/L 173 µg Al/L	3.75 mg TI/L 433 µg Al/L
Time weighted mean measured Al conc.	0.21 µg Al/L	0.96 µg Al/L	2.87 µg Al/L	7.09 µg Al/L	18.9 µg Al/L
Time weighted mean recalculated test item concentration	1.87 µg TI/L	8.33 µg TI/L	14.9 µg TI/L	61.4 µg TI/L	164 µg TI/L
% of nominal	1.90	3.47	4.15	4.10	4.36

 

Survival, growth and reproduction data.

(SD = standard deviation. Number ofD. magnaper concentration: n = 10. TWM = Time weighted

mean.)

Concentration	Parental survival	Growth (length on day 21)	Age at first brood	Cumulative offspring per female	Intrinsic rate of increase
(TWM)	(%)	Mean±SD (mm)	Mean±SD (days)	Mean±SD (Ind.)	Mean±SD (Ind./day)
Control	100	4.96±0.35	10.3±1.14	78.3±11.9	0.297±0.018
0.21µg Al/L 11.1 µg TI/L	100	4.73±0.49	10.8±1.64	77.3±11.8	0.292±0.025
0.96 µg Al/L 8.33 µg TI/L	100	4.76±0.21	11.0±0.71	79.5±14.6	0.288±0.022
2.87 µg Al/L 14.9 µg TI/L	100	4.86±0.21	10.5±0.94	85.7±11.5	0.307±0.022
7.09 µg Al/L 61.4 µg TI/L	90	4.77±0.30	10.6±0.88	81.6±17.8	0.296±0.028
18.89 µg Al/L 164 µg TI/L	100	4.47±0.45	10.2±0.82	55.5±19.2	0.281±0.032

 

Effect summary table.

(Based on concentrations calculated from time weighted mean concentrations (TWM). n.d. = not

determined due to mathematical reasons)

Concentration	Parental survival	Growth (length on day 21)	Age at first brood	Cumulative offspring per female	Intrinsic rate of increase
EC10 (95% CL)	n.d. (n.d.)	≥18.9 µg Al/L (n.d.)	-	5.25 µg Al/L (n.d.)	n.d. (n.d.)
NOEC	≥18.9 µg Al/L	7.09 µg Al/L	≥18.9 µg Al/L	7.09 µg Al/L	≥18.9 µg Al/L

Validity criteria fulfilled:

yes

Description of key information

NOEC (21 d): 1.5 mg/L (nominal), read across

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.5

Additional information

Experimental results on the chronic toxicity of aluminium tris(dihydrogen phosphate) (CAS 13530-50-2) to aquatic invertebrates are not available. The assessment is therefore based on read-across data. In accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across to the structurally related Aluminium metaphosphate (CAS 13776-88-0) was conducted to fulfil the standard information requirements. In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for aquatic toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across). According to Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 substances can be considered to be similar if their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity. For further details please see chapter 6.1 of the IUCLID file.

The study on the chronic toxicity of aluminium metaphosphate was conducted according to OECD guideline 211 (Simon, 2016). Daphnia magna was exposed to nominal test substance concentrations of 0.096, 0.24, 0.60, 1.50, and 3.75 mg/L. The aluminium concentrations in the test solutions were determined analytically. The mean measured aluminium concentrations were 0.21, 0.96, 2.87, 7.09 and 18.9 µg/L. During the exposure period of 21 days effects on survival, growth and reproduction of Daphnia magna were recorded. Based on the reproduction a NOEC of 1.5 mg/L (nominal test substance concentration) was observed.