> Can anybody here share some details about the potential problems
> of using organophosphates in general and Checkmite in particular?

Some perspective:

Coumaphos is EPA approved for direct application to
beef and lactating dairy cattle, sheep, goats, swine, horses
and poultry to control a wide range of external parasites
http://www.mindspring.com/~cherubini/coumaphos.jpg

In addition, veternarians have access to formulations of
coumaphos that can be fed to cattle to control gastrointestinal
worms http://www.speclab.com/compound/c56724.htm

Other organophosphates are EPA approved for spraying
directly on human food for protection again food
infesting insects. Take Reldan (chlorpyrifos-methyl)
http://www.geocities.com/Eureka/Plaza/8603/label_rel.html
It can be diluted with water and sprayed on barley, oats, rice,
sorghum and wheat.'

Or if one is a corn farmer Actellic (pirimiphos-methyl)
http://www.geocities.com/Eureka/Plaza/8603/label_act.html
can be diluted with water and sprayed on corn going into storage
for insect control.

 In the recent past, Malathion was approved for spraying on
almonds and peanuts going into storage for insect control.  Also
(by prescription only) for application to the heads of children
to control lice.

Paul Cherubini
Shore Chemical Company
Turlock, Calif.