Formaldehyde

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Only few experimental data are presented in the study. No analytical monitoring was performed; methanol content of the test substance is not given. However, the deficiencies do not affect the validity of the study.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

(1981)

Deviations:

yes

Remarks:

no information about number of animals per vessel, no analytical monitoring.

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): Formaldehyde
- Analytical purity: No data
- Composition of test material, percentage of components: No data
- Lot/batch No.: No data

Analytical monitoring:

no

Details on sampling:

not applicable

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: No data; formaldehyde is not volatile from aqueous solution at the concentration range tested.

Test organisms (species):

Daphnia pulex

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia pulex De Geer
- Source: laboratory culture
- Age at study initiation: neonates <24 hours old
- Feeding during test: No

ACCLIMATION
- Type and amount of food: dry yeast solution and unicellular grenn algae Scenedesmus quadricauda, no data about amount
- Feeding frequency: three times a week

CULTURING CONDITIONS
- cultured in 3-L aquariums and beakers

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

127 mg CaO/L

Test temperature:

20±1 °C

pH:

8.4

Dissolved oxygen:

No data

Salinity:

Not applicable

Nominal and measured concentrations:

Not applicable

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: open, formaldehyde is not volatile from aqueous solution at the concentration range tested
- Material, size, headspace, fill volume: No data
- Aeration: No
- No. of organisms per vessel: No data
- No. of vessels per concentration (replicates): No data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Stream surface water: COD: 5 mg/L; BOD: 5; N Kjeh = - , NH4+-N <0.04 mg/L; NO3- - N: 0.90 mg/L; NO2 - - N <0.002 mg/L; Total solids, 105°C: -; Fixed solids, 550 °C: -; Phenols < 0.005 mg/L; Formaldehyde <0.05 mg/L
- Alkalinity: No data
- Ca/Mg ratio: No data
- Conductivity: No data
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 12 h daily
- Light intensity: fluorescent lamp (40 W, 4500 K) and Sylvania lamp (40 W)

EFFECT PARAMETERS MEASURED : immobility, sampled after 48 hours

TEST CONCENTRATIONS: No single test concentrations reported

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

1.9 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

5.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mobility

Remarks on result:

other: 95 % c.l.: 4.3-7.8 mg/L

Duration:

48 h

Dose descriptor:

other: EC90

Effect conc.:

16.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mobility

Details on results:

No detailed results from the tested concentrations are presented in the report.
Other biological observations: No data

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

Probit analysis to determine effective concentrations (ECx)

Validity criteria fulfilled:

not specified

Conclusions:

The test results indicate that the test item is acutely toxic towards Daphnia pulex.

Executive summary:

An experimental study similar to OECD guideline 202 (1981) was conducted to assess the toxicity of the test item to aquatic invertebrates. The test organism Daphnia pulex was exposed to the test item for 48 h in a static system. The mobility was observed and the effect values EC50, EC10 and EC90 were derived. An EC50 of 5.8 mg/L was determined by Probit analysis based on the active ingredients.

No analytical monitoring was performed to verify the concentrations. Nevertheless, the test substance concentration can be assumed to be stable during the exposure period. This is due to the low volatilization potential from water (cf. 5.4.2) and the low adsorption potential (cf. 5.4.1). Biodegradation of the test substance during the exposure period cannot be excluded completely (cf. 5.2). Furthermore, it was demonstrated in the frame of a fish test (Bills 1977) that the effect values did not change when an aged test solution was used indicating that the test substance is stable during the incubation period. Therefore, the effects to invertebrates are not underestimated using the nominal values. Based on the results of the experimental study with Daphnia pulex the test item is acutely toxic to aquatic freshwater invertebrates.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

according to guideline

Guideline:

other: APHA-AWWA-WPCF (1989) Standard Methods for the Examination of Water and Wastewater, 17th edn., Washington DC

GLP compliance:

no

Specific details on test material used for the study:

37% formaldehyde solution, reagent grade

Analytical monitoring:

yes

Details on sampling:

in fresh and 24 h old solutions

Vehicle:

no

Test organisms (species):

other: Pinctada fucata martensii (pearl oyster, marine)

Details on test organisms:

TEST ORGANISM
- Age at study initiation: 1 and 2 years old
- Weight at study initiation: mean 18.4 ± 3.4 g (1 year old), mean 51.4 ± 3.4 g (2 years old)
-- Method of breeding: spawned and hatched artificially
- Feeding during test: no

Test type:

semi-static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

20 and 25°C

Nominal and measured concentrations:

nominal: 2, 5, 10, 25, 50, 75, 100, 200 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 L polycarbonate aquaria
- Type: closed
- Renewal rate of test solution: every 24 h
- No. of organisms per vessel: 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: natural seawater, sand filtrated

EFFECT PARAMETERS MEASURED: mortality recorded every 24 h

TEST CONCENTRATIONS: 2, 5, 10, 25, 50, 75, 100, 200 mg/L (formaldehyde, nominal)

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

7.7 mg/L

Nominal / measured:

meas. (not specified)

Remarks on result:

other: 20°C; one-year-old oyster

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

5.3 mg/L

Nominal / measured:

meas. (not specified)

Remarks on result:

other: 25°C; one-year-old oyster

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

10.2 mg/L

Nominal / measured:

meas. (not specified)

Remarks on result:

other: 20°C; two-year-old oyster

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

6.4 mg/L

Nominal / measured:

meas. (not specified)

Remarks on result:

other: 25°C; two-year-old oyster

Details on results:

Variations of the dissolved oxygen concentration and the formaldehyde concentration in the test solutions imply that pearl oyster can defend themselves from toxic effects of formaldehyde by reducing their respiration rate. Furthermore, pearl oysters are capable of lowering the formaldehyde concentration in surrounding water, thus defending themselves.

Conclusions:

The test item is acutely toxic for the test organism

Executive summary:

An experimental study with Pinctada fucata martensii according to APHA-AWWA-WPCF (1989) Standard Methods for the Examination of Water and Wastewater was conducted to assess the toxicity of the test item to saltwater invertebrates (Takayanagi, 2000). In a semi static set-up 1- and 2-year-old test organisms were exposed to 2, 5, 10, 25, 50, 75, 100 and 200 mg/L of the test item for 96 h. The concentrations were monitored analytically, and the mortality was recorded every 24 h. The 1-year-old oysters were the most sensitive in the study with an LC50 of 5.3 mg/L after 96 h. The effect value for the 2-year-olds was slightly higher with 6.4 mg/L but within the same range. Pinctada fucata martensii was the most sensitive of the tested species. Therefore, the EC50 (96 h) for the 1-year-olds was used for further assessment.

Description of key information

Acute toxic for marine and freshwater invertebrates

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Remarks:

Daphnia pulex

Effect concentration:

5.8 mg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

LC50

Remarks:

Pinctada fucata martensii

Effect concentration:

5.3 mg/L

Additional information

Several publications are available which assessed the acute toxicity of the test item to different aquatic fresh- and saltwater invertebrate species (see table 1). The results with the most sensitive species were selected as key studies for freshwater and saltwater each.

Freshwater:

An experimental study similar to OECD guideline 202 (1981) was conducted with Daphnia pulex (Tisler, 1997). The test organism Daphnia pulex was exposed to the test item for 48 h in a static system. The mobility was observed and the effect values EC50, EC10 and EC90 were derived. An EC50 of 5.8 mg/L was determined by Probit analysis based on the active ingredients. This result was the most sensitive value and was therefore used for further assessment.

These results were supported by another publication with Daphnia magna according to the same guideline (OECD 202) and 48 h exposure (Janssen & Persoone 1993). An EC50 of 29 mg/l was observed which indicates lower sensitivity of Daphnia magna in comparison to Daphnia pulex. Slightly lower results were achieved in two publications of Bringmann & Kuehn (1977 and 1982). After 24 h exposure EC50 values of 14.7 and 18.2 mg/L were detected.

Effect values in a similar range were detected in experimental studies with Helisoma sp. After 96 h exposure an EC50 of 37.16 mg/L was observed (Bills, 1977).

No analytical monitoring was performed to verify the concentrations. Nevertheless, the test substance concentration can be assumed to be stable during the exposure period. This is due to the low volatilization potential from water (cf. 5.4.2) and the low adsorption potential (cf. 5.4.1). Biodegradation of the test substance during the exposure period cannot be excluded completely (cf. 5.2). Furthermore, it was demonstrated in the frame of a fish test (Bills 1977) that the effect values did not change when an aged test solution was used indicating that the test substance is stable during the incubation period. Therefore, the effects to invertebrates are not underestimated using the nominal values. Based on the results of the experimental study with Daphnia pulex the test item is acutely toxic to aquatic freshwater invertebrates.

Saltwater:

An experimental study with Pinctada fucata martensii according to APHA-AWWA-WPCF (1989) Standard Methods for the Examination of Water and Wastewater was conducted to assess the toxicity of the test item to saltwater invertebrates (Takayanagi, 2000). In a semi static set-up 1- and 2-year-old test organisms were exposed to 2, 5, 10, 25, 50, 75, 100 and 200 mg/L of the test item for 96 h. The concentrations were monitored analytically, and the mortality was recorded every 24 h. The 1-year-old oysters were the most sensitive in the study with an LC50 of 5.3 mg/L after 96 h. The effect value for the 2-year-olds was slightly higher with 6.4 mg/L but within the same range. Pinctada fucata martensii was the most sensitive of the tested species. Therefore, the EC50 (96 h) for the 1-year-olds was used for further assessment.

Two additional publications with the marine invertebrates Corbicula sp.  (Bills, 1977) and Ceriodaphnia dubia (Warne, 1999) are available.  Both species were less sensitive in comparison to Pinctada fucata martensii with LC50 (96h) =50.34 mg/L (Corbicula sp.) and EC50 (48h) =12.98 mg/L (C. dubia).

In conclusion, the test item is acutely toxic to freshwater and marine invertebrates with effect values within the same range.

Table 1 Overview of available data for the assessment of the acute toxicity to aquatic invertebrates (freshwater and saltwater).

Adequacy	Species	Water type	Reference	Result
Key	Daphnia pulex	freshwater	Tisler, 1997	EC50 (48 h) = 5.8 mg/L
Support	Daphnia magna	freshwater	Janssen & Persoone 1993	EC50 (48h) = 29 mg/L
Support	Daphnia magna	freshwater	Bringmann & Kuehn 1982	EC50 (24h) = 14.7 mg/L
Support	Daphnia magna	freshwater	Bringmann & Kuehn 1977	EC50 (24h) = 18.2 mg/L
Support	Helisoma sp.	freshwater	Bills, 1977	LC50 (96h) = 37.16 mg/L
Other	Daphnia magna	freshwater	Dowden, 1965	TLm = 100-1000 mg/L(24h)
Key	Pinctada fucata martensii	saltwater	Takayanagi, 2000	LC50(96 h) = 5.3 mg/L
Support	Corbicula sp.	saltwater	Bills, 1977	LC50 (96h) =50.34 mg/L
Support	Ceriodaphnia dubia	saltwater	Warne, 1999	EC50 (48h) =12.98 mg/L