Mothballs (to rid cockroaches) are safe to use in a home, right?

  • Thread starter kyphysics
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  • #1
Been looking up cockroach solutions and came across the use of mothballs (as they dislike the smell that is apparently poisonous).

Quick question: Given these mothballs are poisonous, how safe is it to use them?

How many would you use and how often - it any/at all? Thanks in advance for your feedback!

eta: Would you use them only outdoors if not indoors?
eta2: One brand on Amazon, Enoz, says it is EPA approved. ...Errrh, does that mean it's safe then? Lots of articles I'm Googling say mothballs are poisonous.

*confused now*
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  • #2
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Yes, the oldstyle mothballs using Naphthalene or Paradichlorobenzene are poisonous. There are newer ones that use different chemicals. I don't know their effectiveness though.

The oldstyle mothballs are useful to keep critters out of your garden, both crawling insects and cats. From a safety standpoint I avoid using them indoors.

Try this site for more info on mothballs. They have an overview and many links for further information. They are a partnership of Oregon State University and the U.S. Environmental Protection Agency.

For indoor use and a little more effort involved, Boric Acid powder is a very good general insecticide and fungicide. The advantages are it pretty much stays in place so it doesn't foul the air, and continues to work almost forever. Not recommended for use in food storage cupboards. In the USA it is sold in Garden Supply stores to fight insects. Many years ago it was also available in Drug stores.

The extra work is it is a contact poison, so you have to put it where the roaches are. Pay attention to where they mostly appear and get the powder into any cracks in the vicinity. It may take some detective work (underneath a countertop for instance, or inside a recently acquired padded chair). If you can't pinpoint a specific area, there are roach traps available (at least in the USA) that you scatter around. The traps that catch the most roaches are closest to their hideout(s).

A few residents of the building I'm in have had roach investations and have used the management-supplied exterminator service. The exterminator sprays some smelly liquid around and tells them to stay out for at least four hours. Then repeats the next 2 or 3 months.

Other residents have used Boric Acid with good results once the hiding places are found. (One area was the crack at the wall and floor behind the refrigerator. Another was between a Granite countertop and the uneven cabinet it was on.) The downside is some roaches will crawl out into the open to die.

Some Boric Acid comments and cautions: Boric Acid, at least in the past, was commonly the active ingredient in Eye Wash products, as a saturated solution in water it is effective in controlling fungus infections such as athlete's foot and fungus infection on other body parts. It is quite poisonous if ingested, (when major powder application is needed, I usually use a mask to limit inhalation.) Do not get it on broken skin or in a wound. Wash hands after use.

  • #3
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We had a roach problem when I ran a zebrafish facility at a university.
The fish rooms were warm and humid and there was a fair amount of nice tasty fish food laying around (spillage) which meant there were either lots of roaches (or silverfish).
Since it was in a fish room which was in a biology building with a lot of other animals, we could not use normal poisonous approaches.

We primarily did four things:
  1. Sticky traps (you can buy them or make them (crumple up a piece of packing tape so that the sticky part faces out, put on the floor). these will trap some roaches (but not all). They will indicate locations where the are a problem.
  2. Dry boric acid in places roaches like and other things should not be going. Our favorite was behind drywall. We would either build it in when we had new rooms/buildings made or drill holes through the drywall and put it in through the holes (similar to blowing in insulation material). This worked really well, but it had to b dry because it killed the roaches by sticking to their cuticle and abrading through it as they moved. This caused them to dry out (cutcile is normally water proof).
  3. Poisioned baits. The roaches would be attracted to the bait and eat the poison.
  4. Used particular non-poisonous chemical scents that roaches did not like.
For number 3 and 4, we hired a exterminator that specialized in these approaches. He knew a lot about these particular chemicals.
2 was usually done during construction projects or by campus Physical plant workers. You could also dump boric acid in the top of campus walls, between the drywall since the drywall usually stopped above the easily removable suspended ceilings.
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  • #4
Wrichik Basu
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As many have stated, mothballs (Naphthalene balls) are poisonous. However, in my country, it is widely used in two places: book shelves and cloth cupboards. The primary reason is to keep out silverfish. We used them against cockroaches once, but it didn't work.

In my country, we use certain insecticide sprays ( Those are certainly very poisonous; ingesting them in large amounts may kill you. We never use them in places where we store food/utensils; if we have to, we empty the cupboard completely and then spray, and keep the cupboard open for some days, then wipe it off properly before storing the utensils. But I must admit that they do kill cockroaches; one or two full sprays are good enough for an adult roach.

Sticky baits are a non-poisonous option; they should work. But we have never used them - the thought of picking up a bait with a live cockroach sticking to it is somewhat 🤮

There are some herbal insecticide sprays available, but they generally don't work, at least our experience says so.

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