Formamide

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

Study period:

1988, Mar 02-04

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (exposure concentrations in the test and the stability of formamide were not confirmed by analysis)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

as outlined in Directive 79/831/EEC, Annex V, Part C

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Originally: Institut Nationalde Recherche Chimique Applique, France. Cultured since 1978 in BASF AG laboratories.
- Age at study initiation (mean and range, SD): 2-24 h

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.47 mmol/L

Test temperature:

19-21 °C 

pH:

7.7-8.3

Dissolved oxygen:

8.40-9.46 mg/L

Nominal and measured concentrations:

0 (control), 62.5, 125, 250, 500 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: test tubes with flat bottom
- Material, size, headspace, fill volume: glass, nominal volume 20 mL
- Test volume: 10 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- Biomass loading rate: 2 mL/animal


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: source: tap water; 
pretreatment steps: (1) 6 µm- and charcoal-filtration; (2) H2SO4 was added to reduce alkalinity up to pH 4.3; (3) distilled water was added to reduce water-hardness; (4) water was aerated (oil-free air) until saturated with oxygen; (5) water was stored for at least 24 h for stabilization. 
- Ca/mg ratio: 4:1
- Na/K ratio: 1:10
- Conductivity: 550-650 µS/cm



OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: artificial diffuse light, day/night rhythm = 16/8 h
- Light intensity: ca. 1-8 µE/m2s at a wave length of 400-750 nm


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : swimming ability, pH, oxygen; visually after 0, 3, 6, 24 and 48 hours


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 500 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Reported statistics and error estimates:

Methods to determine EC-values after 48 h:
- EC50: according to Spearman-Kaerber (Sachs L, 1974)
- EC0: highest concentration tested at which <= 10 % of the animals were immobile
- EC100: lowest tested concentration at which 100 % of the animals were immobile
(Sachs L (1974). Angewandte Statistik, 4th edition, Springer Verlag, Berlin)

Mobile daphnids after 48 h of exposure

Nominal concentration mg/L	Mobile daphnids (48 h)
Control	20
62.5	20
125	20
250	20
500	20

pH values

Nominal concentration mg/L	pH (at start of test)	pH (at end of test)
Control	8.05	7.98
62.5	7.85	7.99
125	7.84	7.98
250	7.85	7.97
500	7.85	7.88

Oxygen content

Nominal concentration mg/L	Oxygen (at start of test) mg/L	Oxygen (at end of test) mg/L
Control	9.46	8.68
62.5	9.38	8.64
125	9.29	8.63
250	9.22	8.59
500	9.46	8.40

Effect values after 24 h:
  EC0 = 500 mg/L
  EC50 > 500 mg/L
  EC100 > 500 mg/L

Validity criteria fulfilled:

yes

Conclusions:

Since the substance is hydrolytically stable and has no potential for evaporation, the study is acceptable for assessment although the substance concentrations were not verified by analytical monitoring. The EC0, EC50 and EC100 were all greater than 500 mg/L.

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:

other: Comparable to guideline study with acceptable restrictions

Principles of method if other than guideline:

Acute toxicity study with a marine gammarid

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: prepared from cleaned, natural seawater and from concentrated stock solution containing the test substance
- Controls: natural seawater

Test organisms (species):

other aquatic crustacea: Chaetogammarus marinus

Details on test organisms:

TEST ORGANISM
- Common name: Chaetogammarus marinus (a marine gammarid)
- Length at study initiation (length definition, mean, range and SD): 5 mm +- 1
- Valve height at study initiation, for shell deposition study (mean and range, SD):
- Peripheral shell growth removed prior to test initiation:
- Method of breeding: Test animals grown in a laboratory culture in seawater
- Feeding during test
- Food type: small pieces of Fucus spec. and/or Tetramin were added to each beaker to prevent cannibalism

Test type:

semi-static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

15°C

pH:

7.8-8.3

Salinity:

2.8%

Nominal and measured concentrations:

0 (control), 1000, 1800, 3200, 5600, and 10000 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker covered with a watch glass
- Material, size, fill volume: glass, 1 L
- Aeration: none
- Renewal rate of test solution (frequency): once a day
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 1 animal/100 mL

OTHER TEST CONDITIONS
- Adjustment of pH: No

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The pH and O2 content of the fresh and spent solutions was measured.
After 24, 48, 72 and 96 h, the dead animals were counted and removed, and the condition of the survivors was compared with that of the control
animals in the controls by visual estimation.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

morphology

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

19 031 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Reported statistics and error estimates:

- LC50 values and their confidence intervals were calculated by a parametric model (Kooijman, 1981)

Kooijman SALM (1981) Parametric analyses of mortality rates in bio-assays. Water Res. 15, 107-119

Effect values related to nominal concentrations):

Time (h)	LC50 (mg/L)	Confidence intervals (mg/L)
24	10000
48	25324	4147-154662
72	19031	7009-51672
96	19031	7009-51672

NOEC (96 h) = 1000 mg/L (visual estimation of test animal condition)

Validity criteria fulfilled:

not applicable

Conclusions:

Since the substance is hydrolytically stable and has no potential for evaporation, the study is acceptable for assessment although the substance concentrations were not verified by analytical monitoring. The NOEC and the EC50 at 48 hours were greater than 1000 mg/L.

Description of key information

The substance is not acutely harmful to aquatic invertebrates (both freshwater and marine)

Based on nominal concentrations, the 48 hour NOEC and EC50 for acute effects in Daphnia magna was >500 mg/L (Key 1 study).

Another study in the marine gamarid Chaetogammarus marinus demonstrated an EC50 (96h) value of 19031 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 500 mg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

EC50

Effect concentration:

19 031 mg/L