Toxicity
The EPA has classified it as toxicity class I - highly toxic, because it may cause cancer and there is only a small margin of safety for other effects. Products containing dichlorvos must bear the Signal Words DANGER - POISON.
Dichlorvos is highly toxic by inhalation, dermal absorption, and ingestion. Because dichlorvos is volatile, inhalation is the most common route of exposure. As with all organophosphates, dichlorvos is readily absorbed through the skin.
Symptoms of acute exposure to organophosphate or cholinesterase-inhibiting compounds may include the following: numbness, tingling sensations, incoordination, headache, dizziness, tremor, nausea, abdominal cramps, sweating, blurred vision, difficulty breathing or respiratory depression, slow heartbeat. Very high doses may result in unconsciousness, incontinence, and convulsions or fatality.
Here is the full toxicity report, which is quite extensive:
http://extoxnet.orst.edu/pips/dichlorv.htm