How safe is Borax?

January 13, 2012 6:49 PM

Can any chemistry types help me sort out what I can safely use Borax for?

I am confused about its safe use because it seems it's a laundry additive, but also a rat poison.

Should I use it as a laundry additive?
Should I use it to clean food-related items, like dishes?
What about porous food-related items, like wooden spoons?

Should I use it to make flubber, for a toddler to play with?

posted by xo to science & nature (18 answers total)

Wikipedia
posted by crunchland at 6:53 PM on January 13, 2012

Insecticide
posted by sanka at 7:03 PM on January 13, 2012 [1 favorite]

I borax treat my carpets about every other month. Pringles can with holes cut in the top, sprinkle all over the carpet, let sit for a couple hours, vacuum up.

I have a layer of it under my dog's crate.

I also keep a line of it in front of the door (especially when it rains), there used to always be a line of ants and millipedes coming in that way, now there isn't.

My grandmother says she used to make the boys soak their feet in it to get rid of foot fungus. But not the girls, I always found that interesting.

I don't have kids but I have a small dog and a cat. Neither has shown any ill effects. As you can probably figure, most of the reason I use it is its insecticide properties.
posted by magnetsphere at 7:24 PM on January 13, 2012

I've used Borax to kill ants (sprinkled in cracks), and once in a while in the laundry. But I would not use it in the dishwasher or to wash dishes, myself. It is toxic, and I was just reading something online the other day about a huge fire years ago - the doctors used boric acid to clean the open wounds and people died from boron poisoning.

I would not use it in any product that a child would touch and potentially put it or their fingers in their mouth.

I've also used it to kill ground ivy, mixed with water, but that can't be done more than once in a while or it will kill the grass too. Keep away from kids and pets and never put on an open wound.
posted by Marie Mon Dieu at 7:47 PM on January 13, 2012

Here's the article on boron. More on other poisons (was doing research for a fiction story).
posted by Marie Mon Dieu at 8:04 PM on January 13, 2012

Mixed with peanut butter, gets rid of ants and roaches. However, many pets also like peanut butter, so shouldn't be used in households that have such pets.
posted by kamikazegopher at 8:09 PM on January 13, 2012

It's great to get the mildew stains out when you accidentally leave a load of laundry too long in the washer. If you buy some, there will be a bunch of reccomendations on the box too
posted by dawkins_7 at 8:21 PM on January 13, 2012

Borax is *not* a brand name for boric acid. They are entirely different. Borax is for cleaning. Boric acid is good for getting rid of ants/roaches.
posted by unknowncommand at 8:46 PM on January 13, 2012 [7 favorites]

Thanks unknowncommand. Looks like I wasted some Borax trying to kill some pests.
posted by k8t at 9:10 PM on January 13, 2012 [1 favorite]

Boric acid is a desiccant, which is what kills the pests. It basically dehydrates them to death.
posted by elizeh at 9:21 PM on January 13, 2012

Borax kills ants too, per an entomologist buddy of mine.
posted by janell at 11:10 PM on January 13, 2012

Borax is *not* a brand name for boric acid. They are entirely different.

Not entirely different; borax is the sodium salt of boric acid.

As for toxicity: Rat LD50 for borax is 2.7g/kg, about the same as that of ordinary table salt at 3g/kg. But borax is much slower to eliminate than salt, so it's much easier for it to build up to toxic levels with repeated exposures.

I would certainly not be putting it in any toy that small children might be inclined to nibble.
posted by flabdablet at 11:51 PM on January 13, 2012 [1 favorite]

Non-borax flubber recipe
posted by flabdablet at 11:54 PM on January 13, 2012

You might also care to experiment with psyllium husk, which you can make into fully edible goopy gels of various consistencies.
posted by flabdablet at 11:57 PM on January 13, 2012

Borax does contain boric acid, and you can kill ants with it by mixing it with corn syrup and water as a poison bait trap. I've done it. Several times. Way cheaper than buying a commercially made syrup of boric acid and sugar water (though those also work well).

Borax, as previously mentioned, is about as toxic to humans as table salt and is therefore less dangerous (to people) than many other household insecticides.

You can absolutely use Borax in your dishwasher. The company that makes Borax in fact specifically recommends that you use Borax in your dishwasher. Many commercial dishwashing deterergents contain boric acid. Heck, many commercial dishwashing detergents contain petroleum distillates or bleach. You wouldn't want to drink a full cup of either of those, either, but you've almost certainly already used them before to wash your dishes. As long as your rinse cycle is working properly, using Borax in your dishwasher should be safe and may even be safer as an alternative to other cleaning agents you are already using now.

Commercially made Silly Putty contains boric acid. If you would be willing to let your toddler play with Silly Putty under supervision then letting your toddler play with homemade flubber is not really that different. Personally, I would worried first about the choking hazard aspect of something like that if the toddler is one of those kids who just can't help constantly putting weird stuff in his or her mouth. And of course the toxicity of boric acid would be an added concern if the kid actually swallowed a lot of the flubber. But if the kid is fairly responsible about not eating non-food things and you are willing to supervise closely it could be a totally fine thing to do.
posted by BlueJae at 6:41 AM on January 14, 2012

OP, did you check out the part of the site you linked that mentioned "the many uses" of borax?

I stand corrected regarding borax's use as an insecticide, albeit a potentially less effective one than boric acid alone. I never had luck using borax in this way, so didn't bother to try boric acid alone (which ended up working amazingly well for me). I have always wished that I had known sooner that they weren't identical, hence the overly strident nature of my earlier assertion :)
posted by unknowncommand at 8:02 AM on January 14, 2012

Boric acid =/= borax. Having said that, I wouldn't give a toddler flubber made from it -- while not technically poisonous to humans, it is caustic, and can cause intestinal damage if ingested. (use flabdablet's recipe instead -- we've used that one for years.)

As far as using it in a dishwasher or washing machine, it's probably as safe as what you're using now. I use it regularly when washing especially grungy things, or when washing mildewey stuff (it's great for getting soap scum and mildew off of shower curtain liners). Borax as an insecticide works rather like diatomaceous earth -- it cuts the insect's hard shell, and then dehydrates them. Using it with a sugar solution (or peanut butter) means that more of it gets back to the nest.
posted by jlkr at 9:15 AM on January 14, 2012

I make a homemade laundry detergent out of one cup of Borax, one cup of washing soda (not baking soda) and one Fels-Naptha bar that's been grated.

I started using it a few months ago and it works really well. Super cheap too. Nobody has died, and I have kids who like to chew on their clothes...
posted by TooFewShoes at 10:58 AM on January 14, 2012 [2 favorites]