Spinosad is broken down rapidly by sunlight. In the presence of sunlight,
half-lives on leaves are 2 to 16 days and less than one day in water. When applied to leaves, some spinosad can be absorbed. However, it does not readily spread from leaves to the rest of the plant. In the absence of sunlight, spinosad breaks down very slowly in water. Half-lives of more than 30 days to 259 days have been reported. However, it binds rapidly to sediment. The halflife in sediment, where no oxygen is available, ranges from 161 to 250 days.
Spinosad also sticks to soil and has a very low potential to move through soil towards ground water. In field studies, no break down products of spinosad were found below a soil depth of two feet. In the top layers of soil, spinosad is rapidly broken down by microbes. Soil half-lives of 9 to 17 days have been reported. After it is applied, spinosad is not likely to become airborne.
from this.>
http://npic.orst.edu/factsheets/spinosadgen.html
general info >
https://en.wikipedia.org/wiki/Spinosad
if you read this one,
http://www.cdms.net/LDat/mp0F5022.pdf it does say that burning it MAY produce some toxic substances.
5. FIREFIGHTING MEASURES
Suitable extinguishing media:
To extinguish combustible residues of this product
use water fog,
carbon dioxide, dry chemical or foam.
Unsuitable extinguishing media:
no data available
Special hazards arising from the substance or mixtu
re
Hazardous combustion products:
Under fire conditions some components of this produ
ct may
decompose. The smoke may contain unidentified toxic
and/or irritating compounds. Combustion
products may include and are not limited to: Nitro
gen oxides. Carbon monoxide. Carbon dioxide.
so it has a half life between 2 and 16 days in sunlight, or under grow lights. split the difference and call it a week. so after 1 week you have 50% of what didn't drip off. one week later you have 25%. one week after that you have 12.5%, then 6.25% at one month after spraying.
it's pretty damn rare that i have to spray a plant at all once i put it in flower, and never closer than 2 months before harvest. at two months that would be .35%.....i find that to be an acceptable risk.
