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Norway - Final Regulatory Action
Aminopyralid CAS number:
Date circular:

Chemical name:

Final regulatory action has been taken for the category: Pesticide

Final regulatory action: The chemical is Banned

Use or uses prohibited by the final regulatory action:

All uses.

The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action:

Following a risk assessment, the Norwegian Food Safety Authority adopted the following resolution: Pursuant to Regulation 26 July 2004 No. 1138 on pesticides 4 b) the application for registration of Simplex - aminopyralid + fluroksypyr is rejected.
The underlying reasons were the problematic environmental properties of the active substance aminopyralid. Aminopyralid is highly mobile in soil and will easily be washed down to lower layers of soil and groundwater. Both laboratory studies and model simulations give clear indications of this. Model simulations with the EU FOCUS scenarios as well as Norwegian and Swedish groundwater scenarios show that aminopyralid will reach groundwater in concentrations above the threshold of 0.1 ug/L. In addition, aminopyralid is very persistent in water/sediment tests with an average half-life that clearly exceed the EU criteria for persistence in water.
In addition, it is noted that aminopyralid could pose serious damage to health by prolonged exposure if swallowed and danger of serious damage to eyes.

The reasons for the final regulatory action were relevant to: Environment

Summary of known hazards and risks to the environment:

Environmental fate and behaviour:
Aminopyralid was steadily degraded in soil under aerobic conditions. DT50: 26-147 days. The degradation rate is dependent on temperature. At 10 C the degradation rate is slow. DT50: 402 days. DT90: 1335 days.
The degradation for a whole water/sediment system can be classified as moderate with DT50: 83-104 days when assessing the first phase. Geometric mean was 93 days. When assessing the second phase DT50 was 829-1495 days. Geometric mean was 1113 days.
The leaching behaviour of aminopyralid was estimated using all the nine FOCUS groundwater scenarios and the two recommended models, FOCUS-PELMO and FOCUSPEARL. The use considered was in pasture grass according to the representative GAP, i.e. a single application of 60 g a.s./ha. The cropping scenario chosen for these simulations was "grass/alfalfa", the recommended interception (plant cover) is 90 %, thus the application rate used for all scenarios was 60 g a.s./ha x 10%, or 6 g a.s./ha. These modelling assessments indicate that there are situations where contamination of groundwater is likely to occur.
The trigger of 0.1 ug/L is exceeded in 6 of the 9 FOCUS scenarios. The leaching behaviour of aminopyralid was also estimated using the Norwegian (Heia) and Swedish (nnestad and Krusenberg) groundwater scenarios with the FOCUS crop grass/alfalfa, using the model MACRO. The highest estimated PEC values ranged between 1.6 and 2.1 ug/l for all three scenarios. Surface water FOCUS SWASH was used to estimate the exposure of surface water and sediment. The highest estimated concentration in water overall was predicted to be 22.6 ug a.s./L. The respective concentration in sediment was 3.3 ug a.s./kg dw.
Effects on terrestrial and aquatic organisms:
Aminopyralid showed low acute (LD50: >5000 mg a.s./kg bw) and reproductive (NOEL: 1000 mg a.s./kg bw/d) toxicity to mammals. Calculated TER values (>600 and 298, respectively) are above the relevant triggers. Aminopyralid showed low acute (>2250 mg a.s./kg bw), dietary (>5620 mg a.s./kg diet) and reproductive (NOEC: 2700 mg a.s./kg diet) toxicity to birds. All calculated TER values (>600, >726 and 103-175, respectively) are above the relevant triggers. Aminopyralid showed low contact toxicity to bees (LD50: >100 ug/bee) and low oral toxicity to bees (LD50: >120 ug/bee). Hazard quotients for contact (Qhc) and oral exposure (Qho) are estimated to be 0.6 and 0.5, respectively. These do not exceed the trigger value. In Tier 1 laboratory acute contact toxicity studies, aminopyralid showed low effects on predatory mites (T. pyri) and parasitoids (A. rhopalosiphi). Aminopyralid showed low acute toxicity (LC50: >1000 mg/kg d.w. soil) to earthworms, and TER is estimated to be above the trigger.
Aminopyralid showed low acute toxicity (LC50: >100 mg a.s./L) and low toxicity (NOEC: 1,3 mg a.s./L) in an early life stage test on fish. Calculated TER values are >4902 and 64, which do not exceed the relevant triggers. The formulation Simplex was toxic to rainbow trout (LC50: 7.6 mg/L), but the TER was above the trigger. Aminopyralid showed low acute toxicity (EC50: >100 mg a.s./L) and low reproductive toxicity (NOEC: 100 mg a.s./L). Calculated TER values do not exceed the relevant trigger. Aminopyralid showed moderate toxicity (EC50: 18->100 mg a.s./l) to algae. Calculated TER values are >882, which do not exceed the relevant trigger (<10). Aminopyralid is not expected to bioaccumulate.
The conclusion of the assessment was that aminopyralid is highly mobile in soil and the substance is very likely to reach ground water at concentrations above the threshold of 0.1 g/L. According to water-sediment studies, aminopyralid is persistent.

Expected effect of the final regulatory action in relation to the environment:

Reducing the risk of groundwater contamination of aminopyralid.

Date of entry into force of the final regulatory action: 01/02/2011