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Boric Acid as an Eye Wash

thumbs up sign Hello. For what it may be worth:

According to my old bottle of MK boric acid powder's directions: "AS AN EYEWASH FOR TIRED EYES...Prepare a solution by boiling one level teaspoon to a pint of water. Use warm. Store in sterile container. Prepare sufficient for one day's use and discard unused portion."

Because I have one and want all the more to be careful to avoid a waterborne infection, I use a silver/ceramic filter on my tap water before I boil it with the boric acid powder.


JJ Diliberto
- El Cerrito, California
August 31, 2022

↓ Closely related postings, oldest first ↓

Q. My father mixes boric acid purchased at Phar Mor mixes it with water to wash his eyes. Is this safe even though it is (an insect) poison?

George Kipples
- Naperville Illinois

A. Hi George. What does the label say? -- I'm not really asking for further detail -- I'm making the point that things should be used only for their intended purpose. I feel ann insecticide does not offer enough purity assurance to put in your eyes :-)

When I was younger, boric acid was widely used as an eyewash, and in those days everyone thought it perfectly safe. Most families had a box of it and an eyecup in the hall closet.

opinion! But today the pharmaceutical mega-corps own the FDA and our political system, which has made it impossible for the citizenry to know whether traditional cures are dangerous or whether the mega-corps just decided that cheap generic remedies should be outlawed to protect their $210 per dropper-full business ... because the revolving door bureaucracy has set it up like this:

The FDA calls many traditional cures "new drugs" -- which means they can only be sold after multimillion dollar clinical trials. But because they are traditional, cheap, generic, and non-patentable, obviously there is no one who can recoup the millions of dollars that would be needed to do the testing, so the FDA is able to fulfill the wish of the pharma giants and simply pull the products. It's happened to many traditional cures, although I don't think boric acid powder is actually outlawed for sale like many other traditional cures.

If your government actually cared about high healthcare costs, they'd have the FDA run tests on traditional cures or give a grant to a university to run the tests, so we'd actually know -- but it can't happen until we refuse to vote for any politician who accepts donations from big pharma, the banks, and the megacorps :-)

That leaves us here with "I think it's safe, but I can't claim it, because no clinical tests have been run, nor ever will be".

We see the same corruption in the misuse of our patent system by the pharma industry. The original idea was that public monies would be used to protect an invention from being copied for 20 years in return for the public benefit of everyone being able to freely use it thereafter. But with pharma patent extensions, modifications, tweaks, it seems that no drug of value ever becomes public domain, does it? The benefit all flows in one direction :-(

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey


Albert Deruzzo
- palo Alto, California
October 10, 2022

A. Boric acid has been used for many decades as an eye wash. When used, very diluted in water, it can be used as an emergency eye wash or as eye drops for eye infections. It can also be used safely as a pesticide. It is poisonous to bugs not to humans, and can be used as a pesticide around children. Boric acid also can get through many materials, such as wood and can have lasting effects as a pesticide. It is safe for your father to use this as an eye wash. This method was popularized in the 40's and 50's so his mother probably showed him this. However, why is he using this every day?

Nellie Eshleman
- Gainesville, Florida

Ant killer

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Q. I've used boric acid [affil link] solution for my son when he was an infant (he's now 16). I now have another infant son with an eye infection. I can't remember how much boric acid to use. Anyone?

Patricia Howard
- Fullerton, California

Patricia, I really think you should ask your doctor or a pharmacist. If you get an answer on the internet, from a stranger with no qualifications, and maybe even with a fictitious name and an intent to harm, are you really going to put that in your son's eyes?

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi,

Last year I had an infection in my eye, I don't know what it was, probably a cold or conjunctivitis. My friend's mother used boric acid with water, about half a teaspoon in a cup of water and put it in my eye. Cleared up in about two days. My friend uses boric acid to kill cockroaches; he puts it around the house. It is poisonous to bugs, but not to humans.


Hazel O'Mahony
- New York, New York

A. Boric Acid solution (mix 1 tsp powder in 1 pint boiled water; let cool completely before using) has been used for decades in treating minor eye irritations/infections. Its routine use disappeared with the advent of antibiotics eye drops/ointments. Boric Acid is still a very useful therapy in non serious cases. It is much better than vasoconstrictors (used today for minor irritations), and a hundred times less expensive. Prepare a solution, keep it in a closed glass or plastic container, and use it when needed with an eye cup, Q-tip [affil link] or eye dropper several times a day.

Roberto Lancellotti Maryland
- Burlingame, California

thumbs up sign Works great for cats with eye infections. Apply solution with soft cotton ball.

Janet La Selle
hobbyist - Farmington, New Mexico
October 6, 2021

A. Woah now I came across this thread while searching the web on HOW poisonous boric acid is because it IS poisonous to humans if ingested.

The benefits of using boric acid to control bugs over using Raid or similar product are:

1. Much cheaper. You can buy boric acid powder and mix it with something to make your own bait or buy already prepared harris roach tablets at any grocery store for $3.

2. Bugs do not develop long term resistance to boric acid. The same boric acid has been used for centuries while the chemical insecticides have to constantly change their formulas because bugs become resistant.

3. LESS poisonous if ingested and not poisonous through skin. Chemical insecticides can poison you through contact, but not boric acid. It is harmful to bugs through contact but not to humans and pets. According to Harris Roach Tablets web site, you can eat a whole tablet and it wouldn't harm you. But if you eat a bunch you'd most definitely die. But a child or a dog or a cat wouldn't have an urge to eat a bunch because it tastes awful.

It is safe as an eyewash and in fact is the same thing contained in over the counter Bausch & Lomb eye wash that can be used daily according to the bottle. I have no idea what concentration, although you'd probably want to use distilled water.

Peter Vazquez
- Miami, Florida

Q. We used a Boric Acid eyewash for our toddler (now 16) with good results. I now am caring for a litter of 6 week old kittens who are recovering from an upper respiratory infection. They have received expensive prescribed eye drops for about two weeks. There is some residual eye inflammation left. Does anyone know if this same eyewash could be used for the kittens?


Rose Gilbert
- San Diego, California

Bausch & Lomb Eye Wash

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A. I hear all the time that Boric Acid is poisonous, however Boric Acid is in my contact lens solution made by Bausch & Lomb.

Barbara Gallegly
- Hadley, Michigan

A. My mother used Boric Acid Solution (not the powder, must be the solution). She mixed 50% Boric Acid Solution to 50% water as an eye wash when we were children and it worked every time clearing up "Colds" in our eyes. I have also used this today. Not only in my children, but also as an eye wash for my dogs during the winter months when they get colds in their eyes. And yes, boric acid can be used as a pesticide. It is slow acting but very effective.

Lisa Wright
- Upland, California

Q. I searched in many shops, but I can't find boric acid. Can someone tell me where is it available?



Lea Milic
- Van Nuys, California

A. Boric Acid powder can be purchased at virtually any drugstore. I bought a bottle at Rite-Aid yesterday for my kitten. It comes in a bottle 5-6 inches tall, similar to the type of container in which you might purchase fish-oil capsules or vitamins. It is very inexpensive and effective.

Jodee Gilbert-Uhlman
- Rosamond, California

A. I am 52 years old ... and my mom used boric acid as an eyewash to clear up sties, etc. for us as children. I came to this website today to find info about the water-to-powder mixture and reading one of the responses answered my question right away.
I had difficulty finding boric acid, and the pharmacist within a local Kroger grocery store ordered it for me at $5.99 for 6-oz. powder canister. The pharmacist says it will not harm humans, is good as an eyewash.. because of its antibacterial qualities.
Be sure to boil the water, let it cool, then add the powder mixture. I'm using this to clear up an eye infection in my pet dog.
It really works great !

Gwen Huskey
- Nashville, Tennessee

A. Boric acid is a poison... says so right on the package I just bought, so be careful!

Brian Canali
- Venice, California

A. Thought you all might like some technical information on this subject

... By J.R. Blasius
"Borates, including boric acid, have been used since the days of the ancient Greeks for cleaning, preserving food and other everyday activities.

"Today, boric acid is found in more every day uses and products than ever before. Among them are eye wash solutions, flame retardants, insecticides, glass products and fertilizers. And yet with all these uses over all these years, the question, "Is boric acid toxic?" seems to be raised with regularity every year. Asking "How toxic is boric acid?" is sort of like asking "How hot is hot?"

"The answer clearly needs to be qualified...and, yes, scientists have figured out a means to compare one chemical to the next. In fact, on this scale, scientists and/or regulators can compare most anything that can be swallowed, inhaled or put in one's eyes. The scale I am referring to gives a figure known as the LD50 rating - a dose that would cause the deaths of 50 percent of a specific animal population.

"One method used to determine the LD50 rating for most substances is via laboratory-controlled oral doses to rats. The following table lists the LD50 (oral-rat) for several common substances as published by the Registry of Toxic Effects of Chemical Substances.

"Substance LD50 (milligrams of dose /kg of body weight) Aspirin 1,000 Boric Acid 2,660 Table Salt 3,000 Boron #10 3,500 Baking Soda 4,200 Grain Alcohol 14,000 Based on this data, boric acid and Boron No. 10 are not significantly different in toxicity than common table salt. In addition, both boric acid and Boron No. 10 are less toxic than aspirin. The greater the LD50 rating the safer the substance is.

"When compared to these common household items, boric acid and Boron No. 10 are not particularly dangerous, and, if used properly, will not cause poisoning. It is important to remember that there have been no known deaths resulting from the use of boric acid or Boron No. 10 in mattresses or upholstered furniture or even in their use as an insecticide.

So are borates toxic?
"Certainly, and so is virtually every and anything else you come in contact with. It is simply a matter of quantity, and the simple fact is that exposure to cotton batting treated with borates is a safe exposure that should not cause alarm in anyone.

"In fact, the levels at which these borate products are present in cotton batting make them very effective control agents against dust mites, mold and mildew, all of with can develop in any mattress of any construction. Controlling the spread of dust mites, molds and/or mildews makes for a healthier home and less of a chance for the homeowners to develop allergies.

"If you believe aspirin or table salt is dangerous, poisonous or in some other way life threatening, then you probably should not use borates.

"If, on the other hand, you can rationally look at the comparative data, you will probably come to the conclusion that boric acid and Boron No. 10 are among the safest of choices for making cotton-batting flame retardant."  

--National Cotton Batting Institute

Wilfred Smitherman
- Killeen, Texas

A. Dear Ms. Howard,

My mother always washed her infant children's eyes with boric acid solution in the 40's and 50's. She had five children and never had a problem with it. The doctors at that time recommended it. I followed suit and washed my three children's eyes with it. When they were infants the tear ducts would get clogged and there would be some pus. A little boric acid solution on a fresh cotton ball a couple of times a day would cure the problem. I also used it on our pet dogs and a litter of cats over the years. Works like a charm. We always boiled one cup of water and then added one teaspoon of boric acid water and stirred. It makes a mild solution. I would make a fresh cup after a couple of days. I would keep it in a cup with a saucer on top to keep it clean at room temperature. The 50% boric acid to 50% water solution that I read about in another email sounds too strong to me. Guess you have to use your judgement. Good luck.

Fran Morabito
- Brooklyn, New York

A. I just want to say that the best price I have found for my BA is the one pound plastic bottle of "ENOZ" ROACH AWAY in the garden supply at any Wal-Mart store. Price is only US $2.27.

Melvin Johnson
- Clearwater, Florida

Ed. note: It's probably fine as a roach killer, Melvin. But there are purity standards for chemicals based on their end use, and I would certainly not put this stuff in my eyes even if it is, generally speaking, boric acid.

A. For use as an eyewash it would be wise to obtain medicinal (USP) grade boric acid. A technical grade meant for insecticide may have impurities you wouldn't want in your eye. I believe a nearly saturated solution is what you want, but without any undissolved crystals.

John Reed
- Oak Ridge, Tennessee

Q. I have read all that has been posted about Boric Acid. I am looking to see if anyone has used Boric Acid on Boer Goats as treatment for the eyes? I have a baby Boer with a mild eye infection and several old timers have told me to use it. What do you think? Has anybody out there ever heard of such a thing? Desperate!

Robin Arrowood
- Powder Springs, Tennessee

A. Just adding my 2 cents worth here. In the late 1940's and early 50's, my mother-in-law was a nurse... head of pediatrics at the main hospital in Chicago. She gave me her recipe for a boric acid solution when my kids were small. So, yes, a boric acid solution was and is an accepted and useful medication for irritated eyes. Her "recipe" is for a 2% solution: 1 tablespoon boric acid to 1 pint of purified water (boiled or distilled). Also, if it doesn't clear up the problem, see a doctor.

Donna Winder
- Pine River, Minnesota

thumbs up signVery interesting on boric acid for eye wash. I was at the local Rite aide today and the pharmacists (2) didn't know very much about this treatment. In fact I was in the eye drop section..didn't read what was in the eye drops...and they said there is nothing in that section for "cold in the eyes". Well they are younger and didn't have the wise mothers of the 50's....haha So they referred me to the first aid section to get boric acid powder. Thanks to your website as I didn't know the mixture for homemade solution.

Kay French
- Lebanon, Oregon

thumbs up signMy college daughter called me tonight because her boyfriend has an eye infection from a cold. First thing I told her was to get boric acid. HAHAHA..she did think at first I was crazy but I sent her some of the posts from here. If she didn't believe me she did believe all of you. I remembered using it on the kids when they were little. However, I did tell her washing their hands and not touching the eyes was the best. Just wanted to share this. Patticakes

Patti Forthey
- Illinois

A. If you look up Boric acid in RTECS (Registry of Toxic Effects of Chemical Substances) you will find the complete test data which also list the LDLO/LCLO - LOWEST PUBLISHED LETHAL DOSE/CONC (or the lowest dose known that caused death). The results are as follows:

LDLo - ROUTE: Oral; DOSE: 429 mg/kg [Journal of Toxicology, Clinical Toxicology. (Marcel Dekker, 270 Madison Ave., New York, NY 10016) V.19- 1982- (31,345,1993)] TOXIC EFFECTS: Cardiac - Other changes Kidney, Ureter, and Bladder - Changes in tubules (including acute renal failure, acute tubular necrosis)

LDLo - ROUTE: Skin; DOSE: 2430 mg/kg [JAMA, Journal of the American Medical Association. (AMA, 535 N. Dearborn St., Chicago, IL 60610) V.1- 1883- (128,266,1945)] TOXIC EFFECTS: Gastrointestinal - Hypermotility, diarrhea Skin and Appendages - Primary irritation Nutritional and Gross Metabolic - Body temperature increase

LDLo - ROUTE: Unreported; DOSE: 147 mg/kg ['Poisoning; Toxicology, Symptoms, Treatments,' 2nd ed., Arena, J.M., Springfield, IL, C.C. Thomas, 1970 (2,73,1970)]

LDLo - ROUTE: Oral; DOSE: 200 mg/kg [Lancet. (7 Adam St., London WC2N 6AD, UK) V.1- 1823- (2,162,1917)]

TOXIC EFFECTS: Behavioral - Fluid intake Gastrointestinal - Hypermotility, diarrhea Gastrointestinal - Nausea or vomiting

LDLo - ROUTE: Oral; DOSE: 934 mg/kg [JAMA, Journal of the American Medical Association. (AMA, 535 N. Dearborn St., Chicago, IL 60610) V.1- 1883- (90,382,1928)]

LDLo - ROUTE: Subcutaneous; DOSE: 1100 mg/kg [U.S. Army, Chemical Corps Medical Division Special Report. (Army Chemical Center, MD) (#2,1950)] TOXIC EFFECTS: Behavioral - Tremor Gastrointestinal - Hypermotility, diarrhea Gastrointestinal - Nausea or vomiting

LDLo - ROUTE: Skin; DOSE: 1200 mg/kg [JAMA, Journal of the American Medical Association. (AMA, 535 N. Dearborn St., Chicago, IL 60610) V.1- 1883- (129,332,1945)] TOXIC EFFECTS: Behavioral - Convulsions or effect on seizure threshold Skin and Appendages - Dermatitis, other Nutritional and Gross Metabolic - Body temperature increase

LDLo - ROUTE: Skin; DOSE: 4 gm/kg/4D [Muenchener Medicinische Wochenschrift. (Munich, Fed. Rep. Ger.) V.33-115, 1886-1973. (52,763,1905)]

LDLo - ROUTE: Skin; DOSE: 1500 mg/kg [Quarterly Journal of Pharmacy & Pharmacology. (London, UK) V.2-21, 1929-48. For publisher information, see JPPMAB. (6,714,1933)]

TOXIC EFFECTS: Sense Organs and Special Senses (Nose, Eye, Ear, and Taste) - Conjunctive irritation Lung, Thorax, or Respiration - Respiratory depression Gastrointestinal - Hypermotility, diarrhea

While boric acid when used correctly is great stuff, it most certainly can be toxic even fatal. SO BE CAREFUL not to keep this where young children can get to it! And read the warnings on the package!

Tammy Steinert
- Norfolk, Virginia



A. My local pharmacist just advised me to use one teaspoon of boric acid in a quart of water for kittens' eyes that are infected. Her caution was not to keep the solution any great length of time in storage. Make new when needed.

Gary Beckwith
- McGill, Nevada

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