Registration Dossier

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
no data available: testing technically not feasible

Marine water

Hazard assessment conclusion:
no data available: testing technically not feasible

STP

Hazard assessment conclusion:
no data available: testing technically not feasible

Sediment (freshwater)

Hazard assessment conclusion:
no data available: testing technically not feasible

Sediment (marine water)

Hazard assessment conclusion:
no data available: testing technically not feasible

Hazard for air

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:
no data available: testing technically not feasible

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

PNECS FOR ENVIRONMENTAL COMPARTMENTS

In general, the available ecotoxicological testing data for the similar substances used in read-across indicate very low ecotoxicity for the substance.

A Water Accommodated Fraction (WAF) approach was taken to testing. The WAF approach was considered the only appropriate protocol given the extremely low water solubility of these substances. QSAR estimates of water solubility for the oxidised oils range from 10EXP(-21) – 10EXP(-12) mg/l based on Log Kow values, to 10EXP(-7) – 10EXP(-6) mg/l based on molecule fragments. In both cases it can be observed that the predicted water solubility is negligible and impossible to assess through direct physical measurements. Thus, a comparison of the available results with the expected solubility of the substance indicates that toxicity would not be expected at water saturation, resulting in a very low expected hazard for ecotoxicity. These findings generally support a Classification of no hazard for aquatic toxicity.

PNECs for environmental compartments (aquatic, sewage treatment plant [STP] microorganisms, sediments, soil and air) have not been developed at this stage due to the low ecotoxicological hazard expected, and because the available test data are not appropriate for PNEC development (i.e.,the results of WAF tests are not considered to be appropriate starting points because the concentration of substance in solution cannot be confirmed). The substances considered are expected to biodegrade in aquatic, STP, sediment and soil compartments, limiting exposure of organisms. For the case of the air compartment, the substance is considered to be virtually non-volatile, meaning that exposure in this compartment is not relevant.

PNEC FOR SECONDARY POISONING

Secondary poisoning is important to consider for substances that may accumulate through the food chain (i.e.,biomagnifying substances), posing a potential risk to higher trophic level organisms through dietary consumption. Chapter R.16 of ECHA’s Guidance for the implementation of REACH (ECHA, 2008a) provides the following “indications” for bioaccumulation potential of a substance:

 

1) it has a log Kow ≥ 3 and a molecular weight below 700 g/mol; or;

 

2) is highly adsorptive; or;

 

3) belongs to a class of substances known to have a potential to accumulate in living organisms; or;

 

4) there are indications from structural features; and

 

5) there is no mitigating property such as hydrolysis (half-life less than 12 hours).

 

The substance does not belong to any class of substances known to have a potential to accumulate in living organisms [3] nor are there any indications for bioaccumulation potential from structural features [4]. Moreover, the substance has a high molecular weight (>700 g/mol, [1]) and negligible water solubility, which means that its bioavailability and potential for adsorption through living membranes is very limited [2]. As a consequence, the risk of secondary poisoning can be discarded and no PNEC is required for secondary poisoning.

Conclusion on classification

The available toxicity values for Daphnia, Algae and Fish indicate that the substance is well above its solubility limit at the loading values. This allows inference that ecotoxicity would not be expected at the limit of water solubility for the substance.

Comparison of the available toxicity values to the T screening criterion from Chapter R.11 of ECHA Guidance (ECHA, 2008d) for acute tests of 0.1 mg/L results in screening conclusion of “presumably not T” for the substance. Due to difficulties in testing, it is generally expected that chronic fish toxicity data would not be available for similar highly hydrophobic substances, or where available, would be based on a WAF approach.

These considerations were deemed to provide sufficient evidence that toxicity will not occur in a chronic test, allowing for a weight of evidence conclusion of “not T” for the substance according to the REACH T Criteria and applicable guidance.

 

Although toxicity values are not available for terrestrial organisms, it is concluded that testing for terrestrial organisms can be waived because the substance will not be directly applied to soil and an indirect exposure to soil via sewage sludge transfer is unlikely since the substance is biodegradable, limiting concentrations in sewage sludge. If small amounts of the substance are present in sewage sludge transferred to soils, the substance would have low bioavailability due to a high degree of sorption to soil organic carbon, and would biodegrade further, limiting exposure by terrestrial plants, invertebrates and microorganisms.