N,N-dimethylformamide

Sediment toxicity

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline without analytical concentration verification

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 219 (Sediment-Water Chironomid Toxicity Test Using Spiked Water)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on sediment and application:

5-7 days before the animals are inserted, a sediment is made up that consists of 5 % peat (NATURANA), 75 % quartz sand (grain size 0.063-0.25 mm), 20 % Kaolin (ARGIREC) and 0.05-0.1 % calcium carbonate (12010 Riedel-de Haën; Batch 60260).

Test organisms (species):

Chironomus riparius

Details on test organisms:

TEST ORGANISM
- Source: first larval stadium cultured in BASF: Agrarzentrum Limburgerhof
- replicates: Per tube 20 larvae in four groups, each consisting of five animals, with the help of a watch glass.
- Handling of egg masses and larvae: As with the acute tests, this takes four days before inserting the egg clutches, which are on the edge of the breeding tank loosened with the finger and rinsed into the pelvis. The next the following day, the newly laid egg laid with a pipette removed and transferred to M4 water to ensure that the Larvae are 2-3 days old on the day of insertion.
- Age of animals at beginning of exposure: max -2 -3 days
- Feeding during test: yes
- Food type: Tetra Min®
- Amount: from DAI 10 0.5-1 mg / larva / day
- Frequency: 3 times per week

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

artificial sediment

Remarks:

contains: 5 % peat (NATURANA), 75 % quartz sand (grain size 0.063-0.25 mm), 20 % Kaolin (ARGIREC) and 0.05-0.1 % calcium carbonate (12010 Riedel-de Haën; Batch 60260). Deionized water reduces the water content of the sediment set to about 30 %

Limit test:

no

Duration:

28 d

Exposure phase:

total exposure duration

Nominal and measured concentrations:

nominal: 0.03 – 0.1 – 0.3 – 1 – 3 g/L

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 600 mL glass beaker with each 100 (± 2) g moist sediment and 400 (± 10) mL M4-water

- Sediment volume: 100 (± 2) g moist sediment
- Weight of wet sediment with and without pore water: 100 (± 2) g moist sediment
- Aeration: yes (HAILEA „Super Silent Power Air Pump“ ACO-9820; RESUN: LP-60 air-pump)

EXPOSURE REGIME
- Per tube 20 larvae in four groups, each consisting of five animals, with the help of a watch glass.
- Feeding regime: yes
- Food type: Tetra Min®
- Amount: from DAI 10 0.5-1 mg / larva / day
- Frequency: 3 times per week
CHARACTERIZATION OF (ARTIFICIAL; delete if not applicable) SEDIMENT
- % dry weight of sphagnum moss peat: 5 %
- Particle size distribution
- % sand: 75 % (grain size 0.063-0.25 mm)
- Composition (if artificial substrate): 5 % peat (NATURANA), 75 % quartz sand (grain size 0.063-0.25 mm), 20 % Kaolin (ARGIREC) and 0.05-0.1 % calcium carbonate (12010 Riedel-de Haën; Batch 60260)
- Moisture: 30 %

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

3 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

emergence rate

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

3 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

development rate

Details on results:

Most eggs have a normal appearance and size and are located itself on the edge of the crystallizing dish. Eggs laid on the water surface or at the bottom are partially or completely infertile. In the treatment groups 0.3 and 3 g / L more egg clutches were sterile as fertile.

DMF	Appearance						Location
g/L	normal		short		wrenched / deformed		on the edge		Bottom, surface
	fertile	infertile	fertile	infertile	fertile	infertile	fertile	infertile	fertile	infertile
Control	6	2	0	2	0	4	6	5	0	3
0.03	9	4	1	1	0	4	9	3	1	6
0.1	8	4	0	0	0	0	7	4	1	1
0.3	4	9	0	1	0	4	4	11	0	3
1	7	7	0	0	0	1	7	6	0	2
3	2	1	0	1	0	8	2	6	0	4

Validity criteria fulfilled:

yes

Conclusions:

NOEC (28 d) = 3000 mg/L (effect: emergence rate),
NOEC (28 d) = 3000 mg/L (effect: development rate)

Executive summary:

Possible toxic effects of DMF to sediment dweller Chironomus riparius during an exposure period of 28 days was investigated in a study according to OECD Guideline 219.

Per tube ,containing artificial sediment, 20 larvae in four groups, each consisting of five animals were used. Five concentrations (0.03 – 0.1 – 0.3 – 1 – 3 g/L) were tested.

Most eggs have a normal appearance and size and are located itself on the edge of the crystallizing dish.  Eggs laid on the water surface or at the bottom are partially or completely infertile. In the treatment groups 0.3 and 3 g / L more egg clutches were sterile as fertile.

Dimethylformamide has no significant influence on hatching and development of the larvae or mosquitoes. Thereby the following effect concentrations are derived: NOEC (28 d) = 3000 mg/L (effect: emergence rate), NOEC (28 d) = 3000 mg/L (effect: development rate rate).

Reference 2

Endpoint:

sediment toxicity: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline study without analytical concentration verification

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD 202

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Chironomus riparius

Details on test organisms:

TEST ORGANISM
- Common name: Chironomus riparius
- Source: first larval stadium cultured in BASF: Agrarzentrum Limburgerhof
- Age of animals at beginning of exposure: no information
- Feeding during test: no
- aeration during test: no

ACCLIMATION
- Acclimation period: three days before test start
- Acclimation conditions (same as test or not): same as test

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Remarks:

M4-Medium

Duration:

48 h

Exposure phase:

total exposure duration

Test temperature:

18-22 °C

Nominal and measured concentrations:

- nominal: 5.27 – 7.90 – 11.85 – 17.78 – 26.67 g/L (based on literature data)

Details on test conditions:

TEST SYSTEM
- Test container (material, size):
- Sediment volume: no sediment
- Overlying water volume: 2 mL
- Aeration: no

EXPOSURE REGIME
- No. of organisms per container (treatment): 20 (5 animals counts as one replicate)
- No. of replicates per treatment group: 5
- Feeding regime: no

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219): M4 water

OTHER TEST CONDITIONS
- Photoperiod: 16h: 8 h rhythm, light dark

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

9 050 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

5 270 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Validity criteria fulfilled:

yes

Conclusions:

EC50 (48 h) = 9050 mg/L
NOEC (48h) = 5270 mg/L

Executive summary:

Possible acute toxic effects of DMF to sediment dweller Chironomus riparius during an exposure period of 48 hours was investigated in a study according to OECD Guideline 202.

20 animals were used for each concentration (5.27 – 7.90 – 11.85 – 17.78 – 26.67 g/L), whereby 5 animals come in one replica each. M 4 water was used. During the experiment, the test vessels were not ventilated and the animals were not fed. The test duration was 48 hours.

After 24 and 48 hours, it was checked how many animals were motionless or showed abnormal behavior.

The following endpoints were determined:

EC₅₀ (48 h) = 9050 mg/L

NOEC (48h) = 5270 mg/L

Description of key information

- NOEC (28 d) = 3000 mg/L for Chironomus riparius (OECD Guideline 219, static, non-GLP)

- EC₅₀ (48 h) = 9050 mg/L for Chironomus riparius (OECD Guideline 202, static, non-GLP); Using the reported EC₅₀of 9050 mg/L, the EC₅₀sediment can be reported as 7279 mg/kg sediment ww and the EC₅₀sediment amounts to 33485 mg/kg sediment dw

- NOEC (48h) = 5270 mg/L for Chironomus riparius (OECD Guideline 202, static, non-GLP); The NOEC sediment can be reported as 2413 mg/kg sediment ww and the NOEC sediment amounts to11100 mg/kg sediment dw

Key value for chemical safety assessment

EC50 or LC50 for freshwater sediment:

33 485 mg/kg sediment dw

EC10, LC10 or NOEC for freshwater sediment:

11 100 mg/kg sediment dw

Additional information

In a diploma thesis prepared at BASF SE in 2008 (Jarosz, 2008), acute as well as chronic tests on Chironomus riparius were conducted. The EC₅₀ of the acute test was 9050 mg/L, the NOEC for emergence as well as for development was 3000 mg/L.

Details on the short-term study:

Possible acute toxic effects of DMF to sediment dweller during an exposure period of 48 hours was investigated in a study according to OECD Guideline 202.

20 animals were used for each concentration (5.27 – 7.90 – 11.85 – 17.78 – 26.67 g/L), whereby 5 animals come in one replica each. M 4 water was used. During the experiment, the test vessels were not ventilated and the animals were not fed. The test duration was 48 hours.

After 24 and 48 hours, it was checked how many animals were motionless or showed abnormal behavior.

The following endpoints were determined:

 

EC₅₀ (48 h) = 9050 mg/L

NOEC (48h) = 5270 mg/L

EC₅₀sed calculation via Equilibrium Partioning Method (EPM) (referring to Equation R.10 -2):

 

EC₅₀ mg/kg wet sediment = K_{susp water}/RHO _susp x EC₅₀ mg/L x 1000

With:

1)     RHO _susp (bulk density of wet suspended matter) = 1150 kg /m³

2)     Referring to Equation R.16-6:

Kp_susp (partition coefficient solid-water in suspended matter) = Foc_susp (weight fraction organic carbon in suspended soil) * K_oc (partition coefficient organic carbon-water)

Referring to Equation R.16-7:

K_{susp water} (suspended matter-water partitioning coefficient) = F_watersusp (fraction water in suspended matter) + F_solidsusp (fraction solids in suspended matter) * (Kp_susp/1000) * RHOsolid = 0.925 (m³/m³)

Using the reported EC₅₀ of 9050 mg/L, the EC₅₀ sediment can be reported as 7279 mg/kg sediment ww.

 

Calculation referred to dry sediment:

According to the Technical Guidance Document on Risk Assessment (TGD), wet sediment consists of 90 % v/v water (density 1 kg/L) and 10 % v/v solid particles (density 2.5 kg/L), which results in a wet density of (0.9 x 1) + (0.1 x 2.5) = 1.15 kg/L. The dry weight is consequently 0.25 kg/ (per liter wet sediment) and the ratio wet:dry is 1.15/0.25 = 4.6. By applying this multiplication factor, the EC₅₀ sediment amounts to 33485 mg/kg sediment dw.

Details on the long-term study:

Possible toxic effects of DMF to sediment dweller during an exposure period of 28 days was investigated in a study according to OECD Guideline 219.

Per tube, containing artificial sediment, 20 larvae in four groups, each consisting of five animals were used. Five concentrations (0.03 – 0.1 – 0.3 – 1 – 3 g/L) were tested.

Most eggs have a normal appearance and size and are located itself on the edge of the crystallizing dish.  Eggs laid on the water surface or at the bottom are partially or completely infertile. In the treatment groups 0.3 and 3 g / L more egg clutches were sterile as fertile.

Dimethylformamide has no significant influence on hatching and development of the larvae or mosquitoes. Thereby the following effect concentrations are derived: NOEC (28 d) = 3000 mg/L (effect: emergence rate), NOEC (28 d) = 3000 mg/L (effect: development rate rate).

NOECsed calculation via Equilibrium Partioning Method (EPM) (referring to Equation R.10-2):

NOEC mg/kg wet sediment = Ksusp water/RHO susp x NOEC mg/L x 1000

With:

1)     RHO susp (bulk density of wet suspended matter) = 1150 kg /m³

2)     Referring to Equation R.16-6:

Kp_susp (partition coefficient solid-water in suspended matter) = Foc_susp (weight fraction organic carbon in suspended soil) * K_oc (partition coefficient organic carbon-water)

Referring to Equation R.16-7:

Ksusp water (suspended matter-water partitioning coefficient) = Fwater_susp (fraction water in suspended matter) + Fsolid_susp (fraction solids in suspended matter) * (Kp_susp/1000) * RHOsolid = 0.925 (m³/m³)

The NOEC sediment can be reported as 2413 mg/kg sediment ww.

 

Calculation referred to dry sediment:

According to the Technical Guidance Document on Risk Assessment (TGD), wet sediment consists of 90 % v/v water (density 1 kg/L) and 10 % v/v solid particles (density 2.5 kg/L), which results in a wet density of (0.9 x 1) + (0.1 x 2.5) = 1.15 kg/L. The dry weight is consequently 0.25 kg/ (per liter wet sediment) and the ratio wet:dry is 1.15/0.25 = 4.6. By applying this multiplication factor, the NOEC sediment amounts to 11100 mg/kg sediment dw.