222 OP

Long-term toxicity to aquatic invertebrates

Description of key information

At the limit concentration of 100 mg/L of the test item, no biologically or statistically significant effects were determined. The No Observed Effect Concentration (NOEC) and the Lowest Observed Effect Concentration (LOEC) were as follows: 
NOEC	:	   100 mg/L
LOEC	:	> 100 mg/L
All provided effect values are based on the nominal concentration of the test item.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

The Daphnia magna Reproduction Test (Semi-Static, 21 d) was conducted as a limit test with the limit concentration of 100 mg/L of the test item according to OECD 211 (2008).

Test species was Daphnia magna STRAUS (Clone 5). Ten daphnids individually held were used for the limit concentration and the control. At the start of the exposure, the daphnids were 2 to 24 h old. The test method was semi-static with renewal of the test solutions three times per week. The aim of the Daphnia Reproduction Test over 21 days was to assess effects on the reproduction capacity and other test item-related effects on parameters such as intrinsic rate of natural increase, occurrence of aborted eggs and stillborn juveniles, time of production of the first brood, adult mortality, dry body weight and length of the parental daphnids.

The content of aluminium of the control and the test item suspension with 100 mg/L substance was analytically verified with avalidated photometric cuvette test on days 0, 9, 14 (fresh media, 0 hours), on days 2, 16 (old media, 48 hours) and on day 12 (old media, 72 hours).

The measured concentrations of the component aluminium in the fresh media (0 h) were the range of 68 to 85 % of the nominal value. The measured concentrations of the component aluminium in the old media (48 and 72 h) were the range of 85 to 99 % of the nominal value, which demonstrates that the test item was fully present throughout the exposure. The lack of the measured values in the fresh media may be explained by inhomogeneity of the test item dispersion.

The results given are based on the nominal concentration of 100 mg/L of the test item.

·  The average values of living juveniles per parental daphnid were 82 for the control and 81 for the limit concentration of 100 mg/L after 21 days. The reproductive output of daphnids in the limit concentration was comparable to the reproductive output of daphnids in the control (t-test,p = 0.05).

·  The coefficient of variation of the number of living offspring produced per parent was 12 % for the control and 5 % for the limit concentration of 100 mg/L.

·  The intrinsic rates of natural increase (IR) of the surviving parent daphnids accounting for generation time and number of offspring were calculated as a measure for population growth and maintenance.The intrinsic rates of the limit concentration were comparable to those in the control(t-test,p = 0.05).

·  No dead juveniles were observed in control and the limit concentration of 100 mg/L. The number of aborted eggs was 4 in the control and 3 in the limit concentration.Related to the total number of produced juveniles (dead + alive) the percentage of dead juveniles and aborted eggs was  1 % at the limit concentration and the control.

·  Four broods were observed during the test period for all parental daphnids. The first brood was released from all parent daphnids in the limit concentration of 100 mg/L and in the control on days 8 and 9.

·  No adult mortality or immobilisation of parental daphnids was observed in the control and the limit concentration.

·  The mean drybody weight and total body lengths of all parental daphnids of the test and the control group were determined at the end of the study.
The mean dry body weight of the parental daphnids was 1.19 mg per daphnid for the control and 1.05 mg per daphnid for the limit concentration of 100 mg/L.
The mean body length of the parental daphnids was 5.23 mm per daphnid for the control and 5.05 mm per daphnid for the limit concentration.

·  No males and ephippia (winter eggs) were observed in the respective control or test groups.

No biologically significant effect could be determined in the limit concentration of 100 mg/L in comparison to the control.

The water quality parameters (pH-value, dissolved oxygen, water hardness and temperature) were within the acceptable limits.

·  In order to prove the validity of the test system and test conditions at the test facility, an acute immobilisation test according to DIN 38412 L 11 is carried out with potassium dichromate as reference item once per month.
The EC₅₀of the reference item at1.73 mg/L (95% confidence limits: 1.67 - 1.79 mg/L)after 24 hours is within the prescribed concentration range of 1.0 - 2.5 mg/L of quality criteria according toAQS P 9/2 (05/1996) for daphnids clone 5 cultured in Elendt M4 medium. The EC₅₀-value of the reference item is also within the recommended range of 0.6 - 2.1 mg/L according to OECD-Guideline 202.

Test species was Daphnia magna STRAUS (Clone 5). Ten daphnids, individually held, were used per concentration level and control. At the test start, the daphnids were 2 to 24 hours old. The study was carried out undersemi-static conditions with renewal of the test solutions three times per week. Aim of the Daphnia Reproduction Test over 21 days was to assess effects on the reproduction capacity and other test item-related effects or parameters such as time of production of first brood, adult mortality, intrinsic rate of natural increase, occurrence of aborted eggs and stillborn

         

Summary of all Test Item Related Effects

(Based on the nominal test item concentration of100 mg/L)

Effects	Control	Nominal Test Item Concentration 100 mg/L	Significance
Mean Number of Juveniles per Producing Parent (Reproduction Rate±SD)	82±9	81 ± 4	no^1)
Coefficient of Variation of theMean Number of Juveniles per Producing Parent	12	5	no
Intrinsic Rate of Natural Increase (Mean±SD)	0.44 ± 0.02	0.44 ± 0.02	no^1)
Number of Stillborn Juveniles and Aborted Eggs	1	1	no
Appearance of First Brood (Mean Day±SD)	8.5 ± 0.5	8.5 ± 0.5	no
Number of Broods	4	4	—
Adult Mortality after 21 Days [%]	0	0	no
Parent Daphnids: Mean Dry Weight [mg]	1.19	1.05	—
Parent Daphnids: Mean Body Length [mm]±SD	5.23 ± 0.25	5.05 ± 0.16	no^1)
NOEC	100 mg/L