Formaldehyde

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted according to OECD Guideline 211 and Good Laboratory Practice

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Degree of purity: 40.1%
Further ingredients: 13.8% methanol, 0.02% formic acid, < 2ppm iron
Lot-No.: SYN 697/09
Supplier: Synthite Limited , Mold Flintshire, United Kingdom
Aqueous solution with a substance concentration between 30 and 40%.

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

The test was performed using concentrations of 1.024, 2.56, 6.40, 16.0, and 40.00 mg/L (geometric series with a separation factor of 2.5).

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna STRAUS (clone 5) of laboratory bred (derived from BASF, D-67117 Limburgerhof; the strain originally derived from
the Institut National de Recherche Chimique Appliquee, France in 1978 and cultivated since then at BASF using medium M4 acc. Elendt) were used for
the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test temperature:

20.3 °C (range: 19.7 - 21.1 °C)

Nominal and measured concentrations:

1.021 mg/L (0.84 mg/L)
2.560 mg/L (2.38 mg/L)
6.400 mg/L (5.88 mg/L)
16.000 mg/L (14.99 mg/L)
40.000 mg/L (not analysed because all animals had died before that date)

Details on test conditions:

The test solutions were prepared freshly every day of the test, and the daphnia were transferred into the fresh medium every day of the test.

Duration:

21

Dose descriptor:

NOEC

Effect conc.:

1.04 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: age of first reproduction

Remarks on result:

other: effect value was recalculated by the applicant based on the amount of active ingredients (40.1 %)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 6.4 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks on result:

other: effect value was recalculated by the applicant based on the amount of active ingredients (40.1 %)

Table 1: Results related to 40 % formaldehyde

Cumulative Offspring of Survivors
NOEC LOEC EC10 EC20 EC50	≥ >  = = =	16.0 mg/L 16.0 mg/L n.d.^2) n.d.^2) n.d.^2)
Mean Offspring of Survivors
NOEC LOEC EC10 EC20 EC50	≥ >  = = =	16.0 mg/L 16.0 mg/L n.d.^2) n.d.^2) n.d.^2)
Mobility/ Mortality
NOEC LOEC EC10 EC20 EC50	= = = = =	n.d.^2) n.d.^2) 13.5 mg/L (10.3-17.6)^1) 16.4 mg/L (12.9 - 20.9)^1) 24.0 ml'.J/L (19.0 - 30.2)^1)

 

¹ Numbers in brackets indicate the lower and upper confidence limits at the 95% confidence level.

² No values are given due to mathematical reasons.

Validity criteria fulfilled:

yes

Executive summary:

An experimental study according to OECD guideline 211 and GLP regulations was conducted with Daphnia magna to assess the chronic toxicity potential of the test item. For this purpose, young female Daphnia (the parent animals) aged less than 24h at the start of the test were exposed to the test item at five concentrations (40 % formaldehyde aqueous solution). The test duration was 21 days. Within that time cumulative living offspring produced per parent animal was recorded for each concentration. The reproductive output of the animals exposed to the different concentrations of the test item was compared to that of the controls in order to determine the lowest observed effect concentration (LOEC) and the no observed effect concentration of the test item (NOEC). The results were recalculated by the applicant based on the amount of active ingredients (40.1 %).  The resulting NOEC was ≥ 6.4 mg/L (active ingredients) based on the reproduction. Besides these two parameters, the EC10, EC20 and EC50 were calculated (see table 1). Test item related effects were not found for the additional endpoint size length and width of animals: There is no statistical evidence between the control and 16 mg/L of the test item representing the highest concentration where all test animals survived. Concerning intrinsic rate representing an optional parameter for side-effects a LOEC of 16 mg/L (6.4 mg/L based on the active ingredients) and a NOEC of 6.4 mg/L (2.56 mg/L based on the active ingredients) were calculated. Concerning age of first reproduction representing an optional parameter for side-effects a LOEC of 6.4 mg/L (2.56 based on the active ingredients) and a NOEC of 2.6 mg/L (1.04 mg/L based on the active ingredients) were calculated. Both LOEC ''values were statistically significant according to Williams Multiple Sequential t-Test Procedure. Compared with the LOECs and NOECs of off-spring production (16 mg/L, 6.4 mg/L based on the active ingredients) the values for age of first reproduction are unexpectedly low. At the highest concentration of 40 mg/L tested, all animals died due to acute toxicity effects.

Within chemical analyses performed with the test solutions at the start of incubation (three times during the test) and after 24 h, respectively, it could be shown that the test item remained stable in the aqueous phase. For this reason, the results of this test are based on the nominal concentrations tested.

Description of key information

According to R7 of ECHA guidance documents reproduction and lethality are the most sensitive endpoints. Where uncertainly arises from which endpoint to consider, the lowest reported value should be used. Therefore, the effect value based on the age of first reproduction (NOEC =1.04 mg/L) was used for further assessment as most sensitive endpoint.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

1.04 mg/L

Additional information

 

The toxicity of an aqueous solution of the test item (40 %) was assessed in an experimental study according to OECD guideline 211 and GLP regulations (SGS, 2008). For this purpose, young female Daphnia (the parent animals) aged less than 24h at the start of the test were exposed to the test item at five concentrations (40 % formaldehyde aqueous solution). The test duration was 21 days. Within that time cumulative living offspring produced per parent animal was recorded for each concentration. The reproductive output of the animals exposed to the different concentrations of the test item was compared to that of the controls in order to determine the lowest observed effect concentration (LOEC) and the no observed effect concentration of the test item (NOEC). The results were recalculated by the applicant based on the amount of active ingredients (40.1 %).  The resulting NOEC was ≥ 6.4 mg/L (active ingredients) based on the reproduction. Besides these two parameters, the EC10, EC20 and EC50 were calculated (see table 1). Test item related effects were not found for the additional endpoint size length and width of animals: There is no statistical evidence between the control and 16 mg/L of the test item representing the highest concentration where all test animals survived. Concerning intrinsic rate representing an optional parameter for side-effects a LOEC of 16 mg/L (6.4 mg/L based on the active ingredients) and a NOEC of 6.4 mg/L (2.56 mg/L based on the active ingredients) were calculated. Concerning age of first reproduction representing an optional parameter for side-effects a LOEC of 6.4 mg/L (2.56 based on the active ingredients) and a NOEC of 2.6 mg/L (1.04 mg/L based on the active ingredients) were calculated. Both LOEC ''values were statistically significant according to Williams Multiple Sequential t-Test Procedure. Compared with the LOECs and NOECs of off-spring production (16 mg/L, 6.4 mg/L based on the active ingredients) the values for age of first reproduction are unexpectedly low. At the highest concentration of 40 mg/L tested, all animals died due to acute toxicity effects.

Within chemical analyses performed with the test solutions at the start of incubation (three times during the test) and after 24 h, respectively, it could be shown that the test item remained stable in the aqueous phase. For this reason, the results of this test are based on the nominal concentrations tested.

 

According to R7 of ECHA guidance documents reproduction and lethality are the most sensitive endpoints. Where uncertainly arises from which endpoint to consider, the lowest reported value should be used. Therefore, the effect value based on the age of first reproduction (NOEC =1.04 mg/L) was used for further assessment as most sensitive endpoint.