What is Allethrin?

Allethrin is a clear amber liquid that is practically insoluble in water. It’s molecular formula is C19H26O3 and is sometimes known as cyclopropanecarboxylic acid. Allethrin is a synthetic pyrethroid, which is a chemical found naturally in the chrysanthemum flower.

What is Allethrin used for?

Allethrin is mainly used as an insecticide to control both flying and crawling insects around the home and industry. It is also used in pet shampoo, lice treatment for people and various other insect repelling products.

Allethrin is used in many products to repel and kill insects
Allethrin is used in many products to repel and kill insects

Allethrin Hazards

Exposure to allethrin can occur by means of; inhalation, ingestion or skin and eye contact.

Inhalation of allethrin mists or fumes, especially for prolonged periods, may cause respiratory discomfort or distress. Symptoms may include; nausea, vomiting, sneezing, nasal stuffiness/discharge and asthma. More serious symptoms may include; hyperexcitability, incoordination, tremors, muscular paralysis and death.

Ingestion of allethrin can be harmful, with animal experiments indicating a lethal dose for humans to be 100g for a typical 70kg male. In smaller doses, the chemical is likely to cause; nausea, vomiting, headaches, other central nervous system disturbances. 

Skin contact with allethrin may be harmful as the chemical can be absorbed by the skin, causing symptoms similar to those shown in inhalation. Allethrin can also cause severe dermatitis and allergic rhinitis and asthma. 

Eye contact with the chemical may cause inflammation and redness of the eye as well as possible temporary vision impairment. 

Allethrin Safety

If allethrin has been inhaled, remove the patient from the contaminated area to the nearest fresh air source and lay them down. Prostheses such as false teeth should be removed as they can block the patients airways. If they are not breathing and you are qualified to do so, perform CPR. Seek medical attention. 

If swallowed, seek medical attention immediately. Urgent hospital treatment is likely required. Where medical attention is more than 15 minutes away (or instructed otherwise), vomiting should be induced (only if conscious), with fingers down the back of the throat. Lean the patient forward or place on their left side to maintain open airways  and prevent aspiration.  

In the event of exposure to skin; remove all contaminated clothing, footwear and accessories and cleanse the affected area with plenty of soap and running water. Contaminated clothing must be washed before wearing again. Seek medical attention in the event of irritation.  

If eye exposure occurs, remove any contact lenses and flush the eye with running water, remembering to wash under the eyelids. Seek medical attention in the event of irritation.

Allethrin Safety Handling

Adequate ventilation should be available when using allethrin and local exhaust ventilation is usually required. 

Emergency eyewash fountains should be accessible in the immediate area of the potential exposure to the chemical.

The recommended PPE for safe handling of allethrin includes:

  • Safety glasses with side shields
  • Chemical goggles
  • Overalls
  • Vapour respirator
  • PVC gloves
  • Safety footwear or safety gumboots

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