Reaction mass of 1,3-diisopropylbenzene and 1,4-diisopropylbenzene

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:

weight of evidence

Study period:

1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

One exposure concentration at the solubility of the TS

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Aliquots of exposure solution were submitted for concentration determinations at 0, 24, and 48 hours. Temperature, dissolved oxygen, and pH were also determined at these same time periods.

Vehicle:

no

Details on test solutions:

Separate tests indicated that the test substance exhibited low solubility and high volatility in water. One gram of the test substance was introduced into an elutriation column and 20 liters of dilution water was continuously circulated through the test chamber and column at a rate of 100 mL/minute in order to maintain exposure concentrations at or near the solubility level throughout the test. Test substance equilibrium was achieved before introducing test organisms and maintained during the exposure (0.91-0.96 mg/L at 0 and 48 hours). No protocol deviations were noted. Study was conducted in duplicate and results were averaged.

Test organisms (species):

Daphnia magna

Test type:

other: Static w/ recirculating elutriation system

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal concentration: 50 mg/L
Measured conc.: 0.93 mg/L (Average of the two replicate means)

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.93 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Average of the two replicate means

Details on results:

The exposed Daphnia exhibited behavior comparable to controls.

Reported statistics and error estimates:

NA, There were no effects noted.

Validity criteria fulfilled:

yes

Conclusions:

No effects were seen at the solubility limit of the test substance.

Executive summary:

m-DIPB was tested for acute toxicity towards Daphnia magna for 48H in a methodology equivalent to OECD 202 guideline and following GLP. The test was conducted using a flow-through, recirculating elutriation system designed to expose the organisms to an exposure concentration at or near the solubility of the test substance. Separate tests indicated that the test substance exhibited low solubility and high volatility in water. Therefore, the measured concentration of m-DIPB (0.93 mg/L) was the result of the low solubility and high volatility of the test substance, but reflected the most effective experimental flow-through design to maximize the exposure concentration. The exposed Daphnia exhibited behavior comparable to controls and it can be stated that m-DIPB is not toxic to Daphnia at solubility limit.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1984

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

One exposure concentration at the solubility of the TS

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

Due to low solubility of the test substance, 2.3 grams of the test substance was introduced into an elutriation column and 23 liters of dilution water was continuously circulated through the test chamber and column at a rate of 100 mL/minute in order to maintain exposure concentrations at or near the solubility level throughout the test. No significant protocol deviations were noted that would affect study results.

Test organisms (species):

Daphnia magna

Test type:

other: Static w/ recirculating elutriation system

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Nominal and measured concentrations:

Nominal concentration: 100 mg/L (concentration assumed to reach equilibrium at the limit of solubility)
Measured conc.: Not conducted

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 3 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 3 mg/L was found to be the limit of solubility of the TS

Details on results:

The exposed Daphnia exhibited behavior comparable to controls.

Reported statistics and error estimates:

NA, There were no effects noted.

Conclusions:

No effects were seen at the solubility limit of the test substance.

Executive summary:

p-DIPB was tested for acute toxicity towards Daphnia magna for 48H in a methodology equivalent to OECD 201 guideline. The test was conducted using a flow-through, recirculating elutriation system designed to expose the organisms to an exposure concentration at or near the solubility of the test

substance. This test system reflected the most effective experimental flow-through design to maximize the exposure concentration. No effects were seen at the solubility limit of the test substance and it can be stated that p-DIPB is not toxic to daphnia at solubility limit.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

See attached document in section 13 "Assessment reports" for justification and rationale of the analogy approach.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.93 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Average of the two replicate means

Validity criteria fulfilled:

yes

Conclusions:

Based on the analogy approach, the target substance and source substances are expected to have same behavior in aquatic compartment. Hence, the EC50 values were derived for the DIPB mixture of isomers from experimental results on the souce substances m-DIPB and p-DIPB. The 48H-LC50 for the target substance was determined to be above 0.93 mg/L, which is considered to be the maximum reachable concentration considering the low solubility and the high volatility of the substances.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: unsuitable test system

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: Balanus amphitrite niveus (nauplii)

Test type:

static

Water media type:

saltwater

Total exposure duration:

1 h

Conclusions:

Nauplii of Balanus amphitrite niveus were exposed to diisopropylbenzene for 1 h and the percentage saturation at which half the larvae (1 h D50) were sent to the bottom of the test device was determined. The 1 h D50 is reported to be 6% (ca. 9 mg/L).

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: study conducted according to guideline (literature not available), the data, however, were evaluated in the frame of the OECD SIDS program and therefore regarded as reliable

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

yes

Test organisms (species):

Daphnia magna

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

0.246 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.392 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.624-0.843 mg/L

Effect Data:
EC50 (24hr) = 0.725 mg/L (mc) (95% C.I.=0.624-0.843 mg/L)
EC0 (24hr) = 0.246 mg/L (mc)
EC50 (48hr) = 0.392 mg/L (mc) (95% C.I.=0.246-0.754 mg/L)
EC0 (48hr) = 0.246 mg/L (mc)
mc: based on measured concentrations

Mortality or Immobility: No test organisms were immobilized at control, solvent control, 0.200 and 0.360 mg/L.  One
individual was immobilized at 0.630 mg/L after 24 hours. All individuals were 
immobilized at 1.10mg/L after 48th hour and 2.00 mg/L on and after  24th hour.

---------------------------------------------------------
Nominal        Cumulative Number of Immobilized Daphnids
                       (Percent Mortality or Immobility)
Conc.       Mean*     -----------------------------------
mg/L        mg/L       24Hour              48Hour
---------------------------------------------------------
Control     ----        0 ( 0 )              0 ( 0 )
Solvent 
 Control    ----        0 ( 0 )              0 ( 0)
0.200       0.134       0 ( 0 )              0 ( 0 )
0.360       0.246       0 ( 0 )              0 ( 0 )
0.630       0.419       1 ( 5 )             12 ( 60 )
1.10        0.754      10 ( 50 )            20 ( 100 )
2.00        1.36       20 ( 100 )           20 ( 100 )
---------------------------------------------------------
*: Mean measured concentration (Geometric Mean)


- Calculation of toxicity values: To calculate toxicity, the mean measured 
concentrations was used.

Water chemistry (pH and DO) and temperature in test: Water chemistry and temperature were measured for control and each concentration at 
the start and 24th hour.
pH: 8.2 - 8.6
DO: 8.4 - 8.8 mg/L
Water Temperature: 19.9 - 20.0 degrees C

Measured Concentrations : 
The test concentrations were measured at the start and 24th hour (before exchange
 of test solution). For some of them, the deviation from the nominal were not 
less than +/- 20%.

---------------------------------------------------------
Nominal     Measured Conc., mg/L       Percent of Nominal
Conc.       ---------------------      ------------------
mg/L         0 hr       24 hr    Mean*    0 hr   24 hr
             Fresh      Old       mg/L    Fresh    Old
---------------------------------------------------------
-Control     <0.002    <0.002    ---       ---     ---
Solvent 
 Control     <0.002    <0.002    ---       ---     ---
0.200         0.159       0.113    0.134    80       57
0.360         0.279       0.217    0.246    78       60
0.630         0.469       0.374    0.419    74       59
1.10          0.863       0.658    0.754    78       60
2.00          1.52        1.21     1.36     76       61
---------------------------------------------------------
Fresh: freshly prepared test solution
Old: test solution after 24 hours exposure
*: Mean measured concentration during 24 hours
(Geometric mean)

Validity criteria fulfilled:

no

Remarks:

All toxic signs were above solubulity limit

Conclusions:

In a study conducted according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), Part I, Daphnia magna were exposed to diisopropylbenzene concentrations for 48 h. The test was conducted using solvent (mixture of a dispersant of HCO40 and DMF) and the estimated values were higher than water solubility, however, analytical monitoring was done. A 48h EC50=0.392 mg/L (95% C.L.: 0.624 -0.843 mg/L; measured concentration) was determined.

Executive summary:

In a study conducted according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test), Part I, Daphnia magna were exposed to diisopropylbenzene concentrations for 48 h. The test was conducted using solvent (mixture of a dispersant of HCO40 and DMF) and the estimated values were higher than water solubility, however, analytical monitoring was done. A 48h EC50=0.392 mg/L (95% C.L.: 0.624 -0.843 mg/L; measured concentration) was determined.

Description of key information

One study was carried out on the mixture of isomers (CERI, 2000) and two other studies were conducted on the isomers 1 ,3-DIPB and 1,4-DIPB respectively (Eastman, 1984, 1986).

The study performed on the mixture used dispersant, and the estimated toxicity values were found to be higher than the water solubility determined by CERI: 48h EC50 = 0.392 mg/L (95% C.L.: 0.624 -0.843 mg/L; measured concentration).

The meta isomer was tested for acute toxicity towards Daphnia magna for 48H in a methodology equivalent to OECD 202 guideline and following GLP. The test was conducted using a flow-through, recirculating elutriation system designed to expose the organisms to an exposure concentration at or near the solubility of the test substance. Separate tests indicated that the test substance exhibited low solubility and high volatility in water. Therefore, the measured concentration of m-DIPB (0.93 mg/L) was the result of the low solubility and high volatility of the test substance, but reflected the most effective experimental flow-through design to maximize the exposure concentration. The toxicity test on p-DIPB was conducted in a similar manner. Therefore, these tests were conducted using the most effective experimental designs. The exposed daphnia exhibited behavior comparable to controls The conclusion was that the meta and para isomers are not toxic to daphnia at solubility limit.