Agriculture Reference
In-Depth Information
DEET is efficiently absorbed across the skin and by the gut. Blood con-
centrations of about 3 mg per liter have been reported several hours after der-
mal application in the prescribed fashion. Toxic encephalopathic reactions
have apparently occurred in rare instances following dermal application,
mainly in children who were intensively treated. The more frequent cause of
systemic toxicity has been ingestion, deliberate in adults, accidental in young
children.
Discretion should be exercised in recommending DEET for persons who
have acne, psoriasis, an atopic predisposition, or other chronic skin condition.
It should not be applied to any skin area that is likely to be opposed to an-
other skin surface for a significant period of time (antecubital and popliteal
fossse, inguinal areas).
Great caution should be exercised in using DEET on children. Only the
products containing the lower concentrations (usually 15%) should be used,
and application should be limited to exposed areas of skin, using as little re-
pellent as possible. If continuous repellent protection is necessary, DEET
should be alternated with a repellent having another active ingredient. If head-
ache or any kind of emotional or behavioral change occurs, use of DEET
should be discontinued immediately.
b. Dimethyl phthalate has been widely used as an insect repellent applied
directly to the skin. Dibutylphthalate is impregnated into fabric for the same
purpose. It is more resistant to laundering than dimethyl phthalate.
The only commercial product-currently available in DMP.
Toxicology and Mode of Action
Dimethyl phthalate is strongly irritating to the eyes and mucous mem-
branes. It has caused little or no irritation when applied to skin, and dermal
absorption is apparently minimal. It has not caused sensitization.
Tests in rodents have indicated low systemic toxicity, but large ingested
doses cause gastrointestinal irritation, central nervous system depression (to
coma), and hypotension. One accidental ingestion by a human resulted in
coma, but recovery was prompt.
13. Benzyl Benzoate
Benzyl benzoate is incorporated into lotions and ointments. This agent
has been used for many years in veterinary and human medicine against mites
and lice.
