Jmagerl wrote:
Does anyone know what the shelf life of a spray can of ant and roach killer
would be? Pyrethin based. I bought a can last summer and it doesn't seem to
be very effective. Would I be better off buying non-pyrethin based products
if I want to carry over from year to year. The same goes for wasp sprays.
You certainly don't want to use a can thats not going to kill anything.



According to OSU:
Shelf life. One should use fresh products whenever possible. Shelf life
of insecticide products is influenced by the formulation, the container
type, storage conditions (temperature and humidity) and time. As a
general rule, an unopened container stored at moderate temperature will
remain effective for 2 to 5 years after purchase. Over time, under poor
storage conditions, the formulation and/or active ingredient can
deteriorate. The formulation can separate or solidify, rendering the
material unsuitable for use. The only way to know for sure if the active
ingredient of a stored product is still effective is to mix and treat a
pest population in a limited area and monitor the results.