Acetamiprid

Fate in :
Acetamiprid is reported to be an insect neurotoxicant but is 300 times less toxic to bees than other neo-nicotinoid insecticides such as imidacloprid and thiamethoxam. It is not bioaccumulative.
The Canadian PMRA recommends buffer zones to reduce the risks to marine or estuarine organisms and terrestrial plants. As acetamiprid is toxic to honeybees, it should not be applied when bees are present in the area being treated.
For drinking water, the estimated environmental concentrations in groundwater was 1.1 μg/L (using the model LEACHM).

Fate in soil:
Under aerobic conditions, acetamiprid is degraded within a few days in soil, mainly by microbial processes. Photolytic and hydrolytic degradation is minimal. Acetamiprid degrades rapidly in the environment to produce soil metabolites that are more persistent and possess low to moderate to high soil mobility. The metabolites have been shown to be toxicologically insignificant.
Laboratory biotransformation studies of acetamiprid were carried out using loam, sandy loam and clay loam soils from the UK, and loamy sand soil from Switzerland. Acetamiprid was found to have a half-life of 1-8 days at 20℃ with the formation of several major transformation products; and a half-life of approximately 7 days in a loam soil from the UK at 10℃,both under aerobic conditions. Although biotransformation studies were not carried out under anaerobic conditions it is expected that acetamiprid will be persistent, based on the anaerobic aquatic biotransformation study. In field studies in Canada, acetamiprid was non-persistent to slightly persistent in soil (DT₅₀ 5.2 - 17.8 days); therefore, no significant carryover of residues to the next field season is predicted. The major transformation products of acetamiprid showed a trend of declining concentrations in soil towards the end of the study. Leaching through the soil layers is unlikely due to the moderately rapid rate of degradation of the parent in soil. DT₅₀ values of 2.8 - 14.1 days were obtained for acetamiprid in field studies in the US, and acetamiprid and its major transformation products were not detected below the 0-15 cm layer of soil.
Adsorption on soil:
K_d 0.34 - 4.1 ml/g, and K_oc 157 - 298 ml/g (for two sandy loam soils, silt loam and clay)
From the K_ocvalues, acetamiprid is moderately mobile in soil and has a moderate potential to partition into aquatic sediment.

Fate in aquatic systems:
Acetamiprid is very soluble in water which suggests high potential to leach in soil or to runoff in surface water. There is no potential for bioaccumulation. It is stable in water at pH 4, 5 and 7 at all temperatures and at pH 9 at 22℃, but is hydrolysed at pH 9 at 35℃ and 45℃ forming two major hydrolytic transformation products. Acetamiprid undergoes phototransformation at pH 7 with a half-life of 34 days.
Acetamiprid is slightly persistent (DT₅₀ = 30 days at 25℃) in aerobic and persistent (DT₅₀ = 365 days at 25℃) in anaerobic sediment-water systems.
Studies showed that acetamiprid poses a moderate risk to vegetative vigour but a low risk to seedling emergence by overspray on non-target vegetation. With regards to seedling emergence, onions were found to be the most sensitive monocotyledon and cucumber the most sensitive dicotyledon. Perennial ryegrass was found to be the most sensitive moncotyledon and lettuce the most sensitive dicotyledon in studies on the vegetative vigour.