1,2,3-trichloropropane

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study according to Good Laboratory Practice and analytical verification of the exposure

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

Principles of method if other than guideline:

In order to limit volatility the exposure was carried out in a closed system. Test material concentration was determined at the beginning and the end of the study in test samples and in 'stability control' samples. To the later there was no food added and helped distinguish potential losses due to volatility or sorption to the food particles.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Test material concentration was determined at the beginning and the end of the study in test samples and in 'stability control' samples. To the later there was no food added and helped distinguish potential losses due to volatility or sorption to the food particles. For determination of the test item concentrations, duplicate samples were taken from the freshly prepared test media of all test concentrations and from the control at one treatment period of the first, second and last week of the test (Day 2, 7 and 14, respectively).To determine the maintenance of the test item concentrations in the test media, stability samples were taken at the end of two test medium renewal periods of 48 hours (Days 9 and 16) and at the end of one renewal period of 72 hours (Day 5).

Details on test solutions:

Prior to the start of the test and prior to each test medium renewal, a stock solution of nominal 100 mg/L was freshly prepared by completely dissolving 220 mg of the test item (dosed in the range of 220.3 to 221.1 mg) in 2200 ml of test water using stirring for 15 minutes at room temperature. Then, adequate volumes of the intensively stirred stock solution were diluted with test water to obtain the desired test concentrations.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia magna Straus. A clone of this species (defined by the supplier as clone 5) was originally supplied by the University of Sheffield/UK in 1992. Since this date, the clone is successfully bred at Harlan Laboratories in culture medium identical to the medium used for the test.
The daphnids used for the test originated from parental daphnids that were at least 14 days old but not older than four weeks and were not first brood progeny. At the start of the test, the test animals were less than 24 hours old.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

Water Hardness: 2.5 mmol/L (= 250 mg/L as CaCO3)
Alkalinity: 0.9 mmol/L

Test temperature:

For the exposure period, test vessels were stored in a temperature-controlled room with continuous monitoring of the room temperature. The water temperature was maintained at 20-21 °C.

pH:

pH measurements are reported for the beginning and end of the media renewal periods. Initial pH was 8.0 +/- 1 and dropped over the course of the 48 to 72 hrs by not more than 0.4 pH units

Dissolved oxygen:

Dissolved oxygen is reported for the beginning and end of the media renewal periods. Initial dissolved oxygen was 8.7 +/- 1 and dropped over the course of the 48 to 72 hrs to not less than 7.0 mg/L.

Nominal and measured concentrations:

Nominal Concentrations: 0, 1.3, 2.8, 6.0, 13, (28) all daphnids were dead at the highest concentration after 24 hrs.
Measured concentrations: 0, 0.91, 2.0, 4.5, 9.6, (n.a.) Values are arithmetic averages of initial and concentration and end of renewal period concentrations.
Initial concentrations were 66 and 78% of nominal concentrations, concentrations at the end of the renewal period were 65 to 72% of the nominal concentrations. The findings suggest that the exposure was maintained and there was no loss of test material to the headspace or due sorption to particles.

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

4.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

9.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

6 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: 1.3-7.5 mg/L

Details on results:

At 9.6 mg/L statistically significant decrease of reproduction and body length was observed.
At 28 mg/L (nominal) all daphnia were dead after 24 hrs.

1,2,3 Trichloropropane

Summary of the results after 21 days of exposure of the test animals:

Concentration of the test item (mg/l)#

	Control	1.3 (0.91)	2.8 (2.0)	6.0 (4.5)	13 (9.6)	28 (n.a.)
Mortality (%) after 21 days of exposure	10	0	0	10	10	100
Mean reproduction rate (living offspring per surviving adult)	122.2	123.8	120.8	119.8	89.3*	**
Mean reproduction rate in % of control	100	101.3	98.8	98	73.1	**
Mean body length of the adults (mm)	4.39	4.31	4.29	4.36	4.11*	**
Mean body length of the adults in % of control	100	98.2	97.6	99.3	93.5	**

Validity criteria fulfilled:

yes

Conclusions:

The effect concentration of chronic toxicity to daphnia magna was determined as EC10=6.0 (1.3-7.5) mg/L (arithmetic mean measured concentration) based on effects on reproduction and growth.

Description of key information

The effect concentration of chronic toxicity to daphnia magna was determined as EC10=6.0 (1.3-7.5) mg/L (arithmetic mean measured concentration) based on effects on reproduction and growth. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

6 mg/L

Additional information

Two relevant long term test with Daphnia magna are available for 1,2,3 -trichlorpropane. One test is deemed reliable and useful for risk assessment (Klimish score = 1). In this test, D. magna were exposed to five concentrations of trichloropropane (99.7%) ranging from 0.91 - 28 mg/L and control dilution water for 21 days in a static renewal test design. Growth and reproduction rate were reduced at 9.6mg/L (arithmetic mean measured concentration) to a statistically significant degree. The NOEC in this study is 4.5 mg/L and the EC10 is 6.0 mg/L (1.3–7.5 mg/L).

One other long-term toxicity value of TCP using a marine invertebrate (Chaetogammarus marinus) is available (Kooijman 1981). The reported endpoint is a 21-day LC₅₀ of 20 mg/L (Kielhorn et al 2003). No NOEC is reported from this study.