Bob.
I had never heard of the fumigant you referred to. I assume you mean:  

PHOSTOXIN® tablets and pellets contain aluminum phosphide (AlP) as their
active ingredient and will liberate phosphine

PESTS CONTROLLED

PHOSTOXIN® has been found effective against vertebrate and the following
insects and their preadult stages – that is, eggs, larvae and pupae:

almond moth 
Africanized bees
Angoumois grain moth 
bean weevil 
bees 
cadelle 
cereal leaf beetle 
cigarette beetle 
confused flour beetle 
dermestid beetle 
dried fruit beetle 
dried fruit moth 
European grain moth 
flat grain beetle 
fruit flies 
granary weevil 
greater wax moth 
hairy fungus beetle rusty grain beetle
Hessian fly 
honeybees infested with tracheal mites
Indian meal moth 
Khapra beetle 
lesser grain borer 
maize weevil 
Mediterranean flour moth
pea weevil 
pink bollworm
raisin moth
red flour beetle
rice weevil
saw-toothed grain beetle
spider beetles
tobacco moth
yellow mealworm


woodchucks
yellowbelly marmots (rockchucks)
prairie dogs (except Utah prairie dogs, Cynomys Parvidens)
Norway rats
roof rats
mice
ground squirrels
moles
voles
pocket gophers
chipmunks

******************************************************
* Full guidelines for BEE-L posting are at:          *
* http://www.honeybeeworld.com/bee-l/guidelines.htm  *
******************************************************