Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.32 mg/L
Assessment factor:
100
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.51 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.032 mg/L
Assessment factor:
1 000
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
19.1 mg/L
Assessment factor:
10
Extrapolation method:
assessment factor

Sediment (freshwater)

Hazard assessment conclusion:
PNEC sediment (freshwater)
PNEC value:
11.5 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
1.15 mg/kg sediment dw
Extrapolation method:
equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:
no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
PNEC soil
PNEC value:
0.34 mg/kg soil dw
Assessment factor:
50

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
PNEC oral
PNEC value:
11.6 mg/kg food
Assessment factor:
90

Additional information

PNECaquatic: Fish were marginally more susceptible to TCPP in the acute tests than the invertebrate, Daphnia magna, and the two species of algae. Given the similarity in acute susceptibility of the three taxa, further testing to determine a threshold concentration for chronic effects in fish could not be justified on animal welfare grounds. 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 0.32 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 100. Following the discussion in the European Union Risk Assessment Report of tris(2 -chloro-1 -methylethyl) phosphate, this value is the PNECaquatic considered as the most appropriate value. In the Risk Assessment Report, an alternative PNEC is derived from the algal NOEC, for the purposes of comparison. This is in accordance with guidance received from TC NES I 05, because the basic guidance from the TGD and the Guidance document on information requirements and chemical safety assessment, Chapter R.10 is not entirely clear as to whether the EC10 or NOEC from the algal study should be used as the main result, in the context of PNEC derivation. In this case, due to the shallow dose-response relationship seen in the study with P. subcapitata, it is considered appropriate to use ErC10 as the primary result of the study. The Daphnia result is more sensitive than the algal ErC10. An alternative PNECaquatic of 0.13 mg/l can be derived from the algal test data by dividing the NOEC of 13 mg/l for effects on P. subcapitata by an assessment factor of 100.

Conclusion on classification

TCPP is inherently biodegradable (95 % within 64 days), has a log Kow of 2.68 and a BCF of 0.8. Acute toxicity to fish, Daphnia and algae (E(L)C50) is reported to be between 51 -131 mg/L. Chronic NOECs are available for algae (72hr-ErC10 = 42 mg/L) and Daphnie (21d-NOEC=32 mg/L).

Based on available information TCPP is not classified for environmental hazards according to Regulation (EC) No 1272/2008 (CLP).

Additional, the classification for the environment is discussed in the European Union Risk Assessment Report (2008).

Following the reasons as discussed in the European Risk Assessment Report of TCPP, the substance should not be classified (see citation below).

"Basis of classification for the environment

Data presented in this report 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:

- 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 quite small (approximately 3-fold).

- Reliable chronic NOECs are 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 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 carried out in the Risk Assessment Report (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 no indication of neurotoxicity in this chemical class from mammalian and avian studies.

- There is therefore no reason to suppose that there will be a significant difference in chronic effects in fish compared to the other taxa. 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, carried out in the Risk Assessment Report).

- 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 tris(2 -chloro-1 -methylethyl) phosphate would be chronically toxic to fish at </= 1 mg/l and testing to confirm this assertion could not be justified on animal welfare grounds."