diuron (ISO); 3-(3,4-dichlorophenyl)-1,1-dimethylurea

Sediment toxicity

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

October 02 - November 12, 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Principles of method if other than guideline:

other: proposed method for Sediment Toxicity Test developed by BBA/IVA ad hoc Working Group "Sediment Toxicity Tests" (Jan. 1992)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sediment and application:

The spiking of the water was set up as follows:
From a stock solution the calculated volume for each concentration were applied to the water column of the test vessels just below the water surface by using a pipette and gently mixing to ensure homogeneous distribution without disturbing the sediment.

Test organisms (species):

Chironomus riparius

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

natural sediment

Duration:

41 d

Exposure phase:

total exposure duration

Duration:

41 d

Dose descriptor:

NOEC

Effect conc.:

> 4 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

emergence rate

Reference 2

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 17 - April 7, 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

ASTM E1383 (Sediment Toxicity Test (Media: Sediment-freshwater))

Version / remarks:

94

GLP compliance:

yes

Analytical monitoring:

yes

Details on sediment and application:

The spiking of the water was set up as follows:
From a stock solution the calculated volume for each concentration were applied to the water column of the test vessels just below the water surface by using a glass pipet or microliter syringe. The compound was mixed into the water column by the gentle aeration in all vessels.

Test organisms (species):

Hyalella azteca

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

natural sediment

Duration:

21 d

Exposure phase:

total exposure duration

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

0.42 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: 95% CL: 0.29 - 0.61, calculated value from mean concentration

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.06 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: mean concentration

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.56 other: mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: mean concentration

Reported statistics and error estimates:

LC50: The Statistical Method was "Moving Average" (Stephen et al.)

Description of key information

Hyallella azteca: NOEC (mortality) = 0.06 mg a.i./L

Additional information

Two reliable chronic sediment toxicity tests with two different species with different living and feeding conditions using spiked water are available for diuron. The study with the midge Chironomus riparius (Heimbach, 1993) was carried out according to a proposed method for a Sediment Toxicity Test developed by BBA/IVA ad hoc Working Group "Sediment Toxicity Tests" (Januar 1992). The resulting NOEC (emergence) value for this water/sediment-system was >4 mg a.i./L diuron. Gagliano & Bowers (1993) performed a Sediment Toxicity Test with Hyalella azteca according to ASTM E1383 -94 and found a NOEC (mortality) of 0.06 mg a.i./L (initial mean measured concentration) based upon no statistically significant difference in survivability and growth at this concentration compared to the control.