WHAT ARE MOTHBALLS AND DO THEY WORK?

A look at the safety issues concerning mothballs, a traditional method of controlling fabric pests in the home.


Mothballs have been around for years. Traditionally they have been made of naphthalene, which gives them their characteristic odour. But are they safe? Do they work? And what are the alternatives?

The use of mothballs to protect clothes from clothes moths (pictured above) and other fabric pests is a common preventative technique and indeed is often recommended by pest managers. However, naphthalene mothballs and flakes are toxic to mammals, certainly by ingestion but also through breathing the vapours. Mothballs undergo ‘sublimation’, meaning they transition from a solid state to a gas. The vapour they release impacts all life stages of the moth, but it is also potentially harmful to humans and their pets.

 

mothballs
Although mothballs are often hung in wardrobes to repel moths, they are best used in enclosed containers

 

The recommended use pattern for mothballs is to place them inside a container which allows the vapour to escape but prevents direct contact with the clothing, and to place the mothball container and clothes inside an enclosed bag or container. Although most labels allow it, they shouldn’t really be hung in wardrobes, as the vapour is more readily inhaled and there is more opportunity for accidental contact or ingestion by children or pets.

Although some naphthalene mothballs still remain on the market in Australia, they have been banned in New Zealand. Camphor moth repellent products are also available. Although it is a natural oil, camphor is toxic when ingested and camphor products have a ‘Poison’ scheduling. In contrast to naphthalene mothballs, camphor labels instruct the products only to be used in well ventilated areas.

Oils of cedar, lavender, cloves and citronellol are commonly used to repel moths. Although these essential oils are often marketed and sold as moth repellents, and they may well work, the amount of actual data in the scientific literature demonstrating their effect is limited.

However, it does appear that they have some repellency effect, but it may not be 100%. It is important to note that they only work if there is a suitable concentration of the fragrance in the air, and that they only repel adult moths. If you have clothes moth larvae in the clothes, they are likely to carry on munching!

The use of essential-oil-based moth repellents can be recommended as part of an overall strategy to prevent clothes moth issues, but if a client is suffering from clothes moth damage, a full inspection and treatment is required.