Tris(2-chloro-1-methylethyl) phosphate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.64 mg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.51 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.064 mg/L

Assessment factor:

500

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

7.84 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

2.92 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

0.29 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

1.7 mg/kg soil dw

Assessment factor:

10

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

PNEC oral

PNEC value:

11 600 g/kg food

Assessment factor:

90

Additional information

Aquatic compartment (incl. sediment)

Study reports have been available for consideration in respect of acute tests with fish, invertebrates, algae and micro-organisms and acute and chronic tests with aquatic invertebrates in fresh water. A NOEC of 32 mg/l and an ErC₁₀ value of 42 mg/l (NOEC 13 mg/l) were determined respectively in the chronic test with Daphnia magna and in the growth inhibition test with the alga Pseudokirchneriella subcapitata. A PNECaquatic of 0.64 mg/l has been derived from the Daphnia test data by dividing the NOEC of 32 mg/l for effects on Daphnia magna reproduction by an assessment factor of 50.

No measured data are currently available for marine organisms therefore the marine PNEC is derived from data obtained for freshwater species (NOEC = 32 mg/l), applying an assessment factor of 500 to give PNECseawater = 0.064 mg/l. In addition, no measured data are currently available for intermittent releases therefore the intermittent releases PNEC is derived from data obtained for freshwater species (NOEC = 32 mg/l), applying an assessment factor of 500 to give PNECseawater = 0.064 mg/l.

The PNEC for STP is 7.84 mg/l based on the IC₅₀ of 784 mg/l and an assessment factor of 100.

No toxicity data are currently available for sediment-dwelling organisms. However, according to the Technical Guidance Document, PNEC_sed can be calculated by the equilibrium partitioning method. Hence, PNEC_sed = 2.92 mg/kg will be used for risk characterisation.

For the PNEC in soil, The availability of a data set that includes acceptable results from three long-term tests with species from at least three trophic levels, means that it is possible to derive a PNEC_soil from the test data by applying an assessment factor of 10 to the lowest chronic NOEC. The resultant PNECsoil is 17/10 = 1.7 mg/kg soil dry weight, equivalent to 1.5 mg/kg soil wet weight.

For the atmosphere, No data are available on the toxicity of TCPP to plants or other organisms exposed via air. Based on its structure, TCPP is not expected to have ozone depleting effects and the low level of exposure makes other effects unlikely.

In the marine environment, there was no measured data are currently available for marine organisms therefore the marine PNEC is

derived from data obtained for freshwater species (NOEC = 32 mg/l), applying an assessment factor of 500 to give PNEC_seawater = 0.064 mg/l. In addition there was neither measured data are currently available for marine sediment organisms therefore the PNEC

is derived by equilibrium partitioning to give PNEC_{marine sediment} = 0.29 mg/kg.

Below table is the summary of the value of PNEC in each compartment.

Compartment	Value of PNEC
Freshwater	0.64 mg/l0.26 mg/l (alternative value for comparison)
Freshwater sediment	2.92 mg/kg wet weight (equilibrium partitioning)
WWTP micro-organisms	7.84 mg/l
Seawater	0.064 mg/l (extrapolation from freshwater)
Marine sediment	0.29 mg/kg wet weight (extrapolation from freshwater)
Soil	1.5 mg/kg wet weight
Secondary poisoning	<11.6 mg/kg food

Conclusion on classification

Data presented in this dossier are consistent with no classification for the environment being necessary. The fish, Daphnia and algae acute E(L)C₅₀ values all fall in the range 10 to 100 mg/l, and there is no evidence of ready degradability in standard tests. However, R52-53 is not applicable for TCPP for the reasons outlined below:

• Reliable chronic NOECs are now available for invertebrates and algae and both are well above 1 mg/l (32 and 23 mg/l respectively). The acute-to-chronic ratios are 4 and 3.6 respectively;

• The acute effect concentrations range from 51 to 131 mg/l (fish and Daphnia respectively). The difference in acute susceptibility across the taxa is therefore actually quite small (approximately 3-fold);

• The tests have been conducted well below the water solubility limit (1080 mg/l), and the low measured BCF values do not suggest that the substance will accumulate over long periods. The acute toxicity therefore probably reflects the effect of uptake at steady state

(i.e. not just partial uptake);

• There is reasonable agreement between the measured acute fish LC50 (51 mg/l) and QSAR predictions (11-21 mg/l, using SRC ECOSAR with measured physicochemical data entered). The substance therefore appears to be behaving in a predictable way

• There is therefore no reason to suppose that there will be a significant difference in chronic effects in fish compared to the other taxa

• Therefore, applying the Daphnia acute-to-chronic ratio to the acute fish result would give a NOEC of approximately 4.5 mg/l. This is very similar to the QSAR estimate of 5.2 mg/l (using SRC ECOSAR with measured physicochemical data entered)

• The acute-to-chronic ratio would be above 50 if the fish NOEC were below 1 mg/l, which is clearly out of line with the observations for Daphnia and algae.

Given these considerations it is unlikely that TCPP would be chronically toxic to fish at <1 mg/l, and TCPP should not therefore be classified.