Kills flea & ticks for 7 days. Prevents flea eggs from hatching for 1 month. Note To Physicians And Veterinarians: This product contains tetrachlorvinphos (an organophosphate) which is a cholinesterase inhibitor. Cholinergic symptoms may include salvation, miosis, incoordination, muscle fasciculation and/or weakness, vomiting, and diarrhea. Atropine is antidotal 2-PAM may be effective as an adjunct to atropine. Call 1-800-275-1414 or a Poison Control Center for further information. Container Handling: If empty: Nonrefillable container. Do not reuse or refill this container. Offer for recycling if available. If partly filled: Call your local solid waste agency for disposal instructions. Never place unused product down any indoor or outdoor drain.