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Toxicity to aquatic algae and cyanobacteria

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In accordance with column 2 of REACH (REGULATION (EC) No 1907/2006) Annex VII the study on toxicity to aquatic algae and cynobacteria (required in section 9.1.2) does not need to be conducted as there are mitigating factors indicating that aquatic toxicity is unlikely to occur:
1. PMVE is expected to rapidly partition to atmosphere.
2. PMVE is not expected to partition to water.
The justifications supporting the above mitigating factors are the following:
The Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a: Endpoint Specific Guidance, Appendix R.7.1-4 indicates that substances with a Henry's Law constant of around 1 hPa m3/mole will rapidly volatilise from water. On the basis of its boiling point of -26 °C (Yaws, Carl L. ©2010 Knovel) that entails a not measurable vapour pressure (i. e. 10^5 Pa) and a limited water solubility (the water solubility value of 31.5 mg/l has been evaluated in a closed system with the atmosphere saturated of PMVE hence it represents an overestimation of the actual water solubility of PMVE in the natural system) PMVE is expected to primarily and rapidly partition to the atmosphere.
The EQC Fugacity III Model confirms that the whole amount of PMVE released to air remains in this compartment. The model was run assuming emission only to air. In case of an accidental emission, PMVE is only released to air, because PMVE is a volatile gas at ambient conditions with a boiling point of -26 °C. Therefore, PMVE would not be expected to partition into water.

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PMVE is a volatile gas at ambient conditions which is expected to primarly and rapidly partition to atmosphere based on its boiling point of -26 °C (Yaws, Carl L. ©2010 Knovel) that entails a not measurable vapour pressure (i. e. 10^5 Pa) and a limited water solubility (the water solubility value of 31.5 mg/l has been evaluated in a closed system with the atmosphere saturated of PMVE hence it represents an overestimation of the actual water solubility of PMVE in the natural system). The Henry’s Law constant of PMVE was calculated to be 32.100 Pa m3/mol (HENRYWIN v3.20, EPI Suite v4.0), suggesting that the substance is expected to rapidly volatilise from water to the air in fact the Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7a: Endpoint Specific Guidance, Appendix R.7.1-4 indicates that substances with a Henry's Law constant of around 1 hPa m3/mole will rapidly volatilise from water. On the basis of the properties of PMVE it is expected that the substance primarily and rapidly partition to the atmosphere. In addition the EQC Fugacity III Model confirms that the whole amount of PMVE released to air remains in this compartment. The model was run assuming emission only to air. In case of an accidental emission, PMVE is only released to air, because PMVE is a volatile gas at ambient conditions with a boiling point of -26 °C.

Hence, due to the gaseous nature of the substance and its partition to the atmosphere, as well as the consequent difficulty to appropriately test PMVE and provide meaningful results, no experimental aquatic toxicity data are reported. However, in order to evaluate the aquatic hazard profile of PMVE despite the fact that it is expected to rapidly partition to the atmosphere compartment, the results of the ECOSAR model (v.1.00, EPI Suite v 4.0) may be applied.

The ECOSAR estimation for acute toxicity for green algae is: 96h EC50 = 90.308 mg/L.

However the result of the ECOSAR model is not considered reliable for the ECOSAR class of chemicals which PMVE is assigned to, since the dataset of substances for this ECOSAR class of chemicals is limited and does not further specify the identity of these substances.