Formaldehyde

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

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

Remarks:

Test substance contains considerable amounts of methanol. No analytical monitoring of test substance concentrations. However, the deficiencies do not affect the validity of the study.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Static exposure to fish over a period of 96 h.

GLP compliance:

no

Remarks:

study was performed before GLP was implemented

Specific details on test material used for the study:

- Technical Formalin:
37 % (w/w) formaldehyde in water, 10-15% methanol
- Aqueous solution with a substance concentration between 30 and 40%.

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

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

Test organisms (species):

Morone saxatilis

Details on test organisms:

TEST ORGANISM
- Common name: Morone saxatilis (striped bass); in the study the species is named by its former name Roccus saxatilis
- Source: Edenton National Fish Hatchery, North Carolina, USA
- Length at study initiation: 60 mm (average)
- Weight at study initiation: 2.7 g (average)
- Feeding during test: No, feeding was stopped 48 hours before start of the test.


ACCLIMATION
- Acclimation period: Before the test fish were held in troughs for 1 week, for acclimation fish were held in the test aquaria for 24 hours before testing.
- Type and amount of food: commercial fish food, no data about amount
- Feeding frequency: no data

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

dilution water 35.0 mg/L CaCO3 equivalents

Test temperature:

21.0 degrees C during test

pH:

dilution water 8.2, no data during test

Dissolved oxygen:

dilution water 7.8 mg/L, not aerated during test

Salinity:

not applicable

Nominal and measured concentrations:

The TS concentration was not monitored

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: open, formaldehyde is not volatile from water in the concentration range tested
- Material, size, headspace, fill volume: 55 L test aquaria, 40 L test water
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 3 test aquaria per concentration
- No. of vessels per control (replicates): 2 controls per test

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water
- Alkalinity: 64.0 mg/L CaCO3 equivalent total alkalinity
- Conductivity: no data
- Culture medium different from test medium: no data

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: no data
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortalities were assessed at 24, 48 and 96 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: No single test concentrations are reported

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

31.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 21.1 - 47.7 mg/L

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

11.8 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 8.5 – 16.7 mg/L

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

6.7 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 3.7 - 11.8 mg/L

Duration:

24 h

Dose descriptor:

other: LC16

Effect conc.:

19.2 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

other: LC16

Effect conc.:

7.4 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

other: LC16

Effect conc.:

4.4 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Basis for effect:

mortality (fish)

Details on results:

no data about other effects

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

Data analysis according to Litchfield JT Jr and Wilcoxon F (1949) A simplified method of evaluating dose-effect experiments. J Pharmacol Exp Ther 96, 99-113

Validity criteria fulfilled:

not specified

Conclusions:

The test item is acutely toxic for aquatic organisms.

Executive summary:

The test organism Morone saxatilis was exposed to the test item (aqueous solution with a substance concentration between 30 and 40 %) for 96 h. All results were reported in ppm of the commercial formulation and not of the active ingredients. The effect values were converted into mg test item/L by the applicant considering a concentration of 37% active ingredients. After 96 h an LC50 of 18 ppm was determined adjusted to the active ingredients content a LC50 of 6.7 mg/L was calculated.

The test substance contains reasonable amounts of methanol (10 - 15%). Due to the low toxic potential of methanol to fish additional toxicity can be (OECD 2004: SIAP of Methanol, http://cs3-hq.oecd.org/scripts/hpv/).

Although no analytical monitoring of the test substance concentration was performed, losses of the test substanc due to volatilization or adsorption are unlikely. This is due to the low volatilization potential from water (Henry’s Law constant = 0.034 Pa m³/mol; Betterton, 1988) and the low adsorption potential (log Koc = 1.202, BASF, 2008). Biodegradation of the test substance during the exposure period cannot be excluded completely (Frauenhofer IME, 2011). Other studies demonstrated indicated the stability of the test item during a similar exposure period (Bills, 1977). Therefore, the effects to fish are not underestimated using the nominal values.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

The methanol content of the test substance is not given. However, this deficiency does not affect the validity of the study.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

no

Specific details on test material used for the study:

Source: Eastman Kodak Co., Purity 90%, no specification of the methanol content is given

Analytical monitoring:

yes

Details on sampling:

Analysis included one spike and one duplicate sample for every 6 to 12 water samples. Calibration curves were established by linear regression of 3 to 5 standards.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The stock solution (8500 mg/L) was prepared from an excess of paraformaldehyde which decomposed and formed formaldehyde gas. The gas was bubbled through water for 50 min and the resulting solution was filtered then adjusted to the desired concentration.

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
Cultured at the US EPA Environmental Research Laboratory-Duluth and the University of Wisconsin-Soperior campus
- Age at study initiation (mean and range, SD): 34 days
- Length at study initiation (length definition, mean, range and SD): mean length 17.3 mm, SD length 2.627 mm
- Weight at study initiation (mean and range, SD): mean weight 0.074 g, SD weight 0.0369 g
- Feeding during test: no

ACCLIMATION
- Acclimation conditions: Adults held at 25°C in flowing water, photoperiod 16-hr light. Asbestos or plastic pipes as spawning substrates.
- Type and amount of food: Frozen adult brine shrimp (Artemia sp.), no data about amount
- Feeding frequency: Two times daily, once daily on weekends. Fish were not fed 24 hr before test.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

50.8 (2.06) mg CaCO3/L

Test temperature:

21.7 (0.31) °C

pH:

6.8 (0.02)

Dissolved oxygen:

7.4 (1.10) mg/L

Salinity:

not applicable

Nominal and measured concentrations:

3.75, 7.50, 15.0, 30.0, 60.0 mg/L + control (nominal)
Percent recovery 95.1% (5.6), N = 6

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Fill volume: 2.8 L
- Renewal rate of test solution: 8.2 per day
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- Biomass loading rate: 0.0322 g / L / day

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Most of the tests used Lake Superior water, filtered through sand and/or cotton fiber filter. A few test used unfiltered Lake Superior water, and in one test the water was sterilized with UV light. Some tests used dechlorinated water from the City of Superior, WI. The two waters were similar in all measured chemical parameters.
- Alkalinity: 37.0 (3.35) mg CaCO3/L
- Conductivity: No data
- Intervals of water quality measurement: Measurements of water temperature, dissolved oxygen, total hardness, total alkalinity and pH were made in each exposure chamber daily where fish survived.

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 16 h photoperiod daily
- Light intensity: no data


EFFECT PARAMETERS MEASURED: Mortality, average weight of fish, standard length. Number of dead fish noted ca. every 24 h, at which time they were also removed.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

24.1 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Remarks:

Formaldehyde 100%

Remarks on result:

other: 95% CI 22.6 - 25.7 mg/L

Reported statistics and error estimates:

LC50 and EC50 with corresponding 95% CI were calculated using the corrected average of the analyzed tank concentrations and the Trimmed Spearman-Karber Method.

Sublethal observations / clinical signs:

Behavioral observations were not recorded.

 

Validity criteria fulfilled:

yes

Remarks:

All validity criteria according the test guideline OECD 203 are met within the study.

Conclusions:

Formaldehyde was found to be toxic towards Pimephales promelas.

Executive summary:

The test species Pimephales promelas was exposed to the nominal test item concentrations: 3.75, 7.50, 15.0, 30.0, 60.0 mg/L and a control (recovery 95.1%)  for 96 h in a flow-through system. The study was conducted similar to OECD guideline 203. The methanol content of the test substance is not given, however, all validity criteria according to OECD are fulfilled and this deficiency does not affect the validity of the study.

The test item found to be acutely harmful to fish. A LC50 value of 24.1 mg Formaldehyde 90%/L was determined. Observation of sub-lethal effects resulted in the same EC50 value.  

A clear concentration-response relationship can be deduced from the study results. While after 96 h only one fish died at 18.7 mg/L in one of the replicates, 100% mortality was observed at the two highest tested concentrations.

The test substance concentration can be assumed to be stable during the exposure period. due to the low volatilization potential from water (Betterton, 1988) and the low adsorption potential (BASF, 2008). Biodegradation of the test substance during the exposure period cannot be excluded completely (Frauenhofer IME, 2011 ).  Analytical monitoring of the actual test concentrations revealed that nominal concentrations were well established, the mean recovery was 95.1%. Therefore, the effects to fish are not underestimated using the nominal values.

 

Description of key information

The test item is acutely harmful to freshwater fish based on several experimental results with different species and acute toxic to marine fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Remarks:

96 h

Effect concentration:

24.1 mg/L

Marine water fish

Marine water fish

Dose descriptor:

LC50

Remarks:

96 h

Effect concentration:

6.7 mg/L

Additional information

Several publications on a wide range of freshwater and marine fish species are available which assess the acute toxic potential of the test item to fish (see table 1).

 

The acute effect values for freshwater species ranged from LC50 = 13.5 mg/L to 122.1 mg/L and were derived from different experimental set-ups and exposure times (48, 72 and 96 h). Although Arapaima gigas was the most sensitive species according to the experimental results with an LC50 (96 h) = 13.5 mg/L(Antrade-Porto, 2018) this study was not used as key studies due to some methodical deficiencies. The effect value for Pimephales promelas was rated with a higher reliability and was used as key value instead (Geiger, 1990) with an LC50 (96 h) = 24.1 mg/L. With exception of the highest found LC50 value (Anguilla rostrata, yellow eel; LC50 (96 h) = 122.1 mg/L; Hinton 1980) all effect values were within the same range (between 10 and 100 mg/L) so the selected key value represents these findings well and is acceptable for further assessments.  All other publications support these findings.

 

For the tested saltwater species, the observed effect values ranged from 6.7 mg/L to 212 mg/L. Whereby the highest effect value derives from a study with an exposure period of 1h and a 72 post-treatment observation period, which was used to determine the LC50 (72 h) (Nasser, 2017). In order to this, this result is not comparable with the other studies in which the exposure times ranged only between 72 and 96 h. The most sensitive saltwater species was Morone saxtalis with an LC50 (96 h) of 6.7 mg/L (Wellborn, 1969). This valuewas selected as key value for marine fish and was used for further assessment. The other publications were used as supporting studies. There is another publication with Morone saxtalis available in brakish water (Reardon, 1980) which observed an even more sensitive effect value with LC50(96 h) = 6.7 mg/L. Since the test organisms in this study were exposed to two different stressors (salinity and test item) this study was rated as not reliable and was only used as additional information.

 

In conclusion the test item is acutely harmful to freshwater fish based on several experimental results with different species and acute toxic to marine fish.

 

 

Table 1: Overview of available publications on the acute toxicity to fish with type of water, effect concentration and exposure time. Selected key studies are highlighted in bold letters.

Species	Water type	Reference	LC50 (in mg/L), exposure time
Ictalurus melas (Ameiurus melas)	freshwater	Bills, 1977	24.81, 96 h
	freshwater	Helms, 1967	18.64, 72 h
Ictalurus punctatus	freshwater	Bills, 1977	26.29, 96 h
	freshwater	Willford, 1966	35.5, 48 h
	freshwater	Clemens, 1958	27.57, 96 h
	freshwater	Howe, 1955	13,99, 96 h
Salmo gairdneri/ Oncorhynchus mykiss	freshwater	Howe, 1955	48.35, 96 h
	freshwater	Bills, 1981	59.54, 96 h
	freshwater	Bills, 1977	47.15, 96 h
	freshwater	Schneider, 1979	63.94, 48 h
	freshwater	Willford, 1966	62.2, 48 h
Salvelinus namaycush	freshwater	Willford, 1966	61.8, 48 h
	freshwater	Bills, 1977	39.96, 96 h
Lepomis macrochirus	freshwater	Helms, 1967	33.14, 72 h
	freshwater	Bills, 1977	39.96, 96 h
	freshwater	Schneider, 1979	27.17, 96 h
	freshwater	Willford, 1966	51.8. 48h
Danio rerio	freshwater	Wellens, 1982	41, 96 h
	freshwater	Resendes, 2018	45.73, 96 h
Leuciscus idus	freshwater	Wellens, 1982	22, 48h
(melanotus)	freshwater	Juhnke, 1978	15-32.4, 48 h
Pimephales promelas	freshwater	Geiger, 1990	24.1, 96 h
	freshwater	Hohreiter, 2001	Review
Notemigonus crysoleucas	freshwater	Helms, 1967	25.68, 72 h
Micropterus dolomieui	freshwater	Bills, 1977	54.34, 96 h
Micropterus salmoides	freshwater	Bills, 1977	57.14, 96 h
	freshwater	Helms, 1967	>41.4, 72 h
Salvelinus fontinalis	freshwater	Willford, 1966	58.1, 48 h
Lepomis cyanellus	freshwater	Bills, 1977	69.13, 96 h
	freshwater	Helms, 1967	>37.26, 72 h
Anguilla rostrata	freshwater	Hinton, 1978 (glass eel)	31.1, 96 h
	freshwater	Hinton, 1979 (black eel)	83.1, 96 h
	freshwater	Hinton, 1980 (yellow eel)	122.1, 96 h
Cyprinus carpio	freshwater	Helms, 1967	>29, 72 h
Tilapia sp.	freshwater	Helms, 1967	>41.4, 72 h
Arapaima gigas	freshwater	Antrade-Porto, 2018	13.5, 96 h
Morone saxatilis	brakish water	Reardon, 1990	6.18, 96 h**
	saltwater	Wellborn, 1969	6.7, 96 h
	saltwater	Bills, 1993	11.11, 96 h
Sphoeroides annulatus	saltwater	Fajer-Avila, 2003	29.23, 72 h
Salmo salar	saltwater	Bills, 1977	69.13, 96 h
Siganus rivulatus	saltwater	Nasser, 2017	212.14, 72 h*

*post-treatment, exposition to test item 1h

** two stressors were used: salinity and test item