Alongside an image of a carved pumpkin in a bucket, the original poster wrote:
Did you know if you give your pumpkins a bleach bath (1 part bleach to 10 parts water) they will last much longer into the season? It kills all of the mold and fungus that causes them to rot. Happy fall!
The image accompanying the claim showed a carved pumpkin; carved pumpkins tend to deteriorate far more quickly than intact ones. It wasn’t clear if the bleach tip was specifically intended for only pumpkins carved into jack-o-lanterns, or if the poster recommended dunking all pumpkins into a bleach bath. (The image in the Facebook post was taken from an October 13 2017 ApartmentTherapy.com post where the “bleach bath” tip appeared.)
Discussion on the Pumpkin Bleach Bath Post: Clever Household Hack or Squirrel Death Penalty?
Perhaps unsurprisingly, the comments section of the post did not appear to be awash in fellow users thanking the poster for her tip or exchanging stories about long-lived Halloween displays.
Instead, most top-level comments debated whether or not the advice posed a fatal risk to hungry creatures. Others mentioned the dilution level (one part bleach to ten parts water), questioning whether or not that endangered potentially endangered wildlife or farm animals who might be fed donated pumpkins:
“PLEASE DO NOT. It will kill animals that eat it. Deer, chipmunks, squirrels, birds, dogs/cats. Please, if you must, spray with vinegar -I am a wildlife biologist, I promise this is important”DIY Halloween Bath Bomb RecipeDIY Halloween Bath Bomb Recipe
“Unfortunately very dangerous for wildlife even if kept away from them while on display it can’t be composted and will end up in landfill where animals will eat it and get very sick or worse.”
“This is not safe for animals that will more than likely snack on your pumpkins when they’re outside unattended or when you get rid of them… please think about your local wild life before doing this!!!”
“Everybody on here is is like don’t soak your pumpkins with a 1 to 10 ratio of bleach to water, but don’t realize a neighbor has 10,000 of bleach water next door in their pool. How many of those animals stop by for a quick drink. Gtfoh”
“PROPERLY DILUTED BLEACH WILL NOT HARM THE SQUIRRELS YOU WALNUT BRAINS. You can literally use BLEACH TABLETS to purify drinking water. Stop word vomiting stuff that you’re not actually knowledge about 🙄”
“If you do this, please remember not to donate them to the pig farmers when they start asking for your pumpkins.”
Earlier Variations on the Pumpkin Bleach Bath ‘Halloween Hack’
On October 28 2011, Today.com advised a solution of one tablespoon of bleach to one quart of water.
You’ve just spent hours carving a freshly-picked pumpkin to perfection. How do you lengthen the life of your prized jack-o-lantern to keep it from shriveling up before Halloween? Try these tips using household products you already have …
- Create a bleach solution using one tablespoon of bleach per quart of water
- Spray the solution on the interior and on all cut out areas
- Let it dry for 20 minutes
That was a ratio of one part bleach to 65 parts water, as one quart contains 65 tablespoons.
ApartmentTherapy.com’s instructions were slightly more involved than those presented in the Facebook post, and the site recommended ongoing pumpkin bleach baths for carved pumpkin maintenance. Also, the ratio was even smaller than one part bleach to ten parts water, recommending a tablespoon of bleach for a gallon of water — although there were 65 tablespoons in a quart, there are 256 tablespoons in a gallon.
The site advised soaking pumpkins in bleach prior to carving for ten minutes or longer:
With your pumpkin still intact, find a bucket or vessel a bit bigger than your gourd. With the pumpkin inside, fill the bucket the rest of the way with a mixture of bleach and water (around 1 to 2 tablespoons of bleach per gallon of water). Let the pumpkin soak for 10 minutes or more, moving the floating pumpkin around as needed. After the bleach bath, make sure to let your pumpkin dry completely before digging in with your carving knife.
If you’re not carving your pumpkin, she’s good to go! Put her on the porch and enjoy the spooky season.
But if you are carving… save that bleach water!
For carved pumpkins, ApartmentTherapy.com advised reserving the “bleach bath” solution in an empty spray bottle, spraying the carved pumpkin after carving, and then re-spraying “every few days” to extend its life:
You can use the same bleach water from your pre-carve bath, or make a fresh mixture with the same ratio (around 1 to 2 tablespoons of bleach per gallon of water), but this time, you’ll want to use it to fill a spray bottle. When you’re done carving your Jack-O-Lantern, spray the bleach mixture all over the open surfaces inside of the pumpkin and within the carved sections. Then leave it upside down for a while until it’s fully dry.
You can use your bleach spray every few days periodically to try and keep your pumpkin looking perfect.
An undated post on BobVila.com recommended bleach as one of a few common household items useful in preserving uncarved pumpkins:
Method 1: Use Bleach
Bleach can scare off fungi and bacteria from your uncarved pumpkin before they transform into mold and rot. Dilute one tablespoon of bleach in four cups of water in a large bucket, then soak the pumpkin in the bleach solution for 20 minutes before removing and drying the pumpkin. If you decorated your uncarved pumpkin, skip the soaking and enlist a can of bleach-based spray to spray the entire surface of the pumpkin before letting it dry.
BobVila.com used the same ratio Today.com provided, but specified “four cups,” or one quart. The site further advised at least twenty minutes of a bleach bath to “scare off” enterprising bacteria and fungi.
Clorox Clarifies the Pumpkin Bleach Bath Controversy
A May 2015 page on Clorox.com ( “How to Preserve a Carved Pumpkin,” under Home > How To > Hacks Crafts DIY > Surprising Uses For Clorox) addressed the use of bleach to extend the life of pumpkins. A search of Clorox.com returned a second page, published on October 28 2016. It covered the same topic and was headlined “Preserving Your Halloween Jack o’ Lanterns.”
Both pages contained the same ratios and roughly identical language, explaining that the tip was an extension of similar advice they offered for extending the lives of cut flowers:
Lots of people know Clorox® Regular Bleach2 can be used to help cut flowers stay beautiful longer, but may not know that the same bleach solution can also help keep a jack o’ lantern from getting fuzzy mold and black mildew inside. It’s super easy! If you’d like to try this, here’s how!
- Measure 3 teaspoons of Clorox® Regular Bleach2 with CLOROMAX®.
- Add bleach to 3 gallons of water.
- Fill a spray bottle with the diluted bleach solution.
- Carve your pumpkin as desired.
- Generously spray inside of your carved pumpkin with the diluted bleach solution.
The ratio offered by the bleach brand was even lower than ApartmentTherapy.com’s ratio of a tablespoon of bleach to a gallon of water. Clorox advised using three teaspoons (or one tablespoon) of standard (not concentrated) bleach to three gallons of water, or one teaspoon per gallon.
Clorox’s recommendation was the most dilute; the Facebook post recommended one part bleach to ten parts water, while Clorox recommended one part bleach to 768 parts water. Although the 2016 post did not address wildlife safety, the 2015 post included the following portion about whether hungry animals were placed at risk by the pumpkin bleach bath:
Don’t worry about bleach hurting squirrels or other curious critters who might take a nibble of your treated pumpkin. During normal household use, bleach breaks down primarily into salt and water. So after using Clorox® Bleach as directed on your pumpkins, the diluted bleach solution will break down to table salt and water when it’s exposed to the air and sun. The pumpkin will just taste a bit saltier than the squirrels were expecting!
Nevertheless, Clorox recommended a far smaller ratio of bleach to water for carved pumpkins. The ratio of bleach in the Facebook post was 77 times higher than the dilution Clorox advised.
Bleach, Food Science, and Pet Safety
A PDF published by food scientists at the University of Oklahoma issued guidelines regarding the safe use of “chlorine bleach for sanitizing raw fruits and vegetables,” writing:
Presumably, the fresh water rinse eliminates any potential problem with residual chlorine. As a practical matter, residual chlorine would in most foods produce highly objectionable flavors and odors well before becoming a safety hazard. Food processing in-plant chlorination systems typically produce water for processing with residual available chlorine levels of no more than 0.5 ppm. For container cooling or general washing, residual available chlorine levels of 2 to 7 ppm are commonly used. Typical municipal water systems produce potable water with a residual available chlorine level of 0.25 to 2 ppm.
Per the guidance, “residual” bleach would — for humans — produce an unpleasant flavor or scent before reaching levels of poisoning risk; diluted bleach is used in food processing at low levels. That said, a number of veterinary advice pages address accidental bleach ingestion in pets and suggest that animals do not always avoid eating objects contaminated with it.
A 2008 toxicology brief about bleach and dogs notes that calculating a precise safe level of diluted bleach is difficult, but extrapolates a rough amount from known levels of human toxicity. That report involved two dogs which were euthanized after consuming undiluted bleach:
While a lethal dose of sodium hypochlorite in dogs is not established in the veterinary literature, extrapolation from a reported lethal dose of sodium chloride of 3.7 g/kg in dogs may be considered. For example, a 40-lb (18-kg) dog would have to ingest about 67 g of sodium chloride to attain this lethal dose. The consumption of 1 L of 6.15% sodium hypochlorite bleach containing 19.1 mg/ml of sodium and 30 mg/ml of chloride would equal the ingestion of 49.1 g of sodium chloride. Assuming the animals only ingested several hundred milliliters of bleach, this amount would not have been sufficient to attain the lethal dose of sodium chloride. However, corrosive injury to the gastrointestinal tract and the development of other metabolic derangements and secondary complications, such as aspiration pneumonia, likely contributed to the severity of the toxicosis. Therefore, it is reasonable to suspect that ingestion of at least several hundred milliliters of bleach resulted in the severe morbidity of these dogs, which led to their euthanasia.
Researchers deduced a lethal dose of 67 grams for a dog weighing roughly 40 lbs.; one teaspoon is equivalent to about 4.2 grams, and a tablespoon contains about 14.6 grams. Although most of the concentrations mentioned above diluted the nearly 15 grams of a tablespoon in either a quart or a gallon, the Facebook post advised one part of bleach to ten parts of water.
Clorox also featured a March 2018 page about pet-safe uses of Clorox bleach, and noting that bleach can serve as “a simple and inexpensive way to help prevent the spread of parvo and other viruses.” That recommended a slightly stronger dilution for disinfecting toys and crates:
Use Clorox® Regular-Bleach to disinfect hard, nonporous surfaces and accessories like crates and toys on a regular basis. You can use a solution of ½ cup of bleach in 1 gallon of water. To kill parvo, soak the items in the solution for 10 minutes, then rinse and air dry.
That solution of half a cup of bleach to a gallon of water was stronger than the pumpkin solution Clorox recommended (a teaspoon per gallon), as there were 32 half cups in a gallon. Therefore, the recommended ratio for pet cleaning was one part bleach to 32 parts of water.
A viral Facebook post was correct in indicating that a “bleach bath” could preserve pumpkins, but its ratio of one part of bleach to ten parts water was far stronger than the ratio recommended by Clorox, on a page designed to sell more bleach. Although other sites (like BobVila.com and ApartmentTherapy.com) recommended bleach baths for all pumpkins, Clorox only advised bleach for carved pumpkins and compared their treatment to that of cut flowers. Clorox said that carved pumpkins could be preserved with a solution of a teaspoon of bleach per gallon, or one teaspoon of bleach to 768 teaspoons of water.