As teh active ingredient is Dichlorvos (Vapona), an organophosphate which was accidentally discovered during the development of a nerve agent for chemical warfare. While effective in the eradication of mites, along with a variety of other "pests", has been found to harbor an acute adverse effect on the neurological system of reptiles. While some have used such with no noticeable ill effect, the risks simply are not worth it and some issues, such as injury to the Jacobson's organ, normally go unnoticed.
Don't just take my word for it, review the following links regarding the Chemical profile and OP poisoning in humans:
pmep.cce.cornell.edu/profiles/insect-mite/ddt-famphur/dichlorvos/insect-prof-dichlorvos.html
www.emedicine.com/neuro/topic286.htm
Personally, I would flip for the Provent-a-Mite, as it will eradicate unseen eggs and is quite safe, so long as it is used as directed, as it is the only USFDA approved product targeted for the eradication of predatory mites in herpetofauna.
While it has been several years since I last incurred a mite infested specimen, I always quarantine new acquisitions for a minimum of 90 days, I like to use a 2% Ivermectin solution, I make this by mixing 2ml of Ivermectin with 98ml of water and using such as a spray. The 2% Ivermectin solution always worked well for me, especially when bringing in recent imports and I have found it to be quite safe to use with Drymarchon spp., which tend to be quite sensitive to other forms of treatment.
You would be well advised to run a search query of the forums, as this issue has been addressed MANY times...
Best regards,
Jeff
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Jeff Snodgres
University of Arkansas
snodgresjeffreys@uams.edu
501.603.1947