Permethrin

Chemical class	Pyrethroid
Chemical Structure
CAS Number	52645-53-1
Mode of action	3A – Sodium channel modulators
Target pests	Insect pests including flies, cockroaches, silverfish, fleas, moths, ants and spiders. Fleas, ticks and other nuisance insects
Hosts	Timber, industrial and domestic premises, trees and stumps, seed potatoes, mushroom beds, dogs, cats and horses
Formulations	Powder, liquid, emulsifiable concentrate, wettable powder, dust, liquid concentrate, topical aerosol spray, shampoo, collar medalion, topical cream, ointment, paste, gel, lotion, ultra-low volume liquid, suspension concentrate (flowable concentrate), topical pump spray, pressurised gas, ear tag and aerosol
Home garden use	Yes
No of Australian Approvals and Registrations	24 active constituents, 295 products
Poison schedule	Schedule 4 Permethrin for human therapeutic use except in preparations containing 5 per cent or less of permethrin. Schedule 5 Permethrin (excluding preparations for human therapeutic use): In preparations containing 25 per cent or less of permethrin; or In preparations for external use, for the treatment of dogs, containing 50 per cent or less of permethrin when packed in single use containers having a capacity of 4 mL or less, Except in preparations containing 2 per cent or less of permethrin. Schedule 6 Permethrin except: When included in Schedule 4 or 5; In preparations for human therapeutic use containing 5 per cent or less of permethrin; or In preparations containing 2 per cent or less of permethrin
Australian Health-based guidance values	ADI: 0.05 mg/kg bw per day (1986) No Australian ARfD established

Key issues

• Although toxicity is relatively low, there is the potential for high levels of exposure due to widespread use pattern.

Stakeholder perspective

• Some stakeholders consider this important as availability of alternatives for mite control in chickens is limited.
• It is used (an off-label use) to control ticks and lice in goats.
• Little use in grain crops.
• One stakeholder expressed reservations about its use in automatic dispensers; but supports the use for pet animals, livestock and farm animals as there are few alternatives for control of ticks.
• It is used by Department of Agriculture and Water Resources as a residual insecticide for interceptions of invertebrates of biosecurity concern and for disinfestation of aircraft and livestock vessels.