Registration Dossier

Diss Factsheets

Administrative data

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:
PNEC aqua (freshwater)
PNEC value:
0.119 mg/L
Assessment factor:
50
Extrapolation method:
assessment factor
PNEC freshwater (intermittent releases):
0.239 mg/L

Marine water

Hazard assessment conclusion:
PNEC aqua (marine water)
PNEC value:
0.012 mg/L
Assessment factor:
500
Extrapolation method:
assessment factor

STP

Hazard assessment conclusion:
PNEC STP
PNEC value:
12 mg/L
Assessment factor:
1
Extrapolation method:
assessment factor

Sediment (freshwater)

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

Sediment (marine water)

Hazard assessment conclusion:
PNEC sediment (marine water)
PNEC value:
0.2 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:
0.336 mg/kg soil dw
Extrapolation method:
equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:
no potential for bioaccumulation

Additional information

Mecoprop-P n-octyl ester hydrolyses rapidly in natural water. Therefore, the hydrolysis product Mecoprop-P acid (MCPP-P acid) was considered as relevant starting point for the environmental hazard assessment of Mecoprop-P n-octyl ester.

 

Conclusion on classification

According to Regulation EC No 1272/2008, the whole class of "esters of Mecoprop and Mecoprop-P" is legally classified as Aquatic Acute 1; H400 "Very toxic to aquatic life" and Aquatic Chronic 1; H410 "Very toxic to aquatic life with long lasting effects" (Index No. 607-423-00-5).

From a chemical point of view, Mecoprop-P n-octyl ester is a member of this class.

 

However, the data presented in this dossier show a different behavior for Mecoprop-P n-octyl ester with no toxicity in the environment up to the limit of the water solubility (no short-term effects on aquatic invertebrates, on fish and on aquatic plants and no long-term effects on aquatic invertebrates).

 

Mecoprop-P n-octyl ester hydrolyses rapidly in natural water. The resulting hydrolysis product is Mecoprop-P acid (MCPP-P acid).

Following the initial degradation step the studies available for the hydrolysis product Mecoprop-P acid (MCPP-P acid) predict the behavior of Mecoprop-P n-octyl ester in the environment.

 

Therefore, as a worst-case scenario the data from Mecoprop-P acid (MCPP-P acid), the hydrolysis product of Mecoprop-P n-octyl ester, are used for assessment. Mecoprop-P acid (MCPP-P acid) is legally classified as Aquatic Chronic 2; H411 "Toxic to aquatic life with long lasting effects" according to Regulation EC No 1272/2008 (GHS) (Index No. 607-434-00-5).

 

However, the data presented in this dossier show a different behavior of Mecoprop-P n-octyl ester and its hydrolysis product Mecoprop-P acid (MCPP-P acid). Therefore, classification may be changed with the following reasons:

- Mecoprop-P n-octyl ester is considered to hydrolyse rapidly in natural water and the hydrolyses product Mecoprop-P is readily biodegradable.

- The most sensitive acute toxicity is to algae: 72h-EC50 of 23.9 mg/L and a 72h-NOEC of 5.96 mg/L were determined on the alga Anabaena flos-aquae.

 

With the data listed above, Mecoprop-P n-octyl ester should be not classified according to Regulation EC No 1272/2008 (GHS).