Preparing meals at home is a great way to enjoy fresh, nutritious food, but safe food handling is essential to prevent food-borne illness. By following a few simple practices, home cooks can reduce the risk of contamination and keep their families healthy.
Fruit and Vegetable Decontamination – The Truth About Pesticides and Bleach
I use bleach in my house. I don’t mention bleach to my sister-in-law because she gets upset at the mere mention of the word. She keeps a strictly herbal household.
To decontaminate produce, I use a wash of what is known as “Dakin solution,” a weak mixture of bleach in water. When I was a public outreach contractor at a chemical weapons demilitarization site, my major task was to teach families in the area how to make Dakin solution. Why? Because Dakin solution neutralizes VX, the deadliest substance ever created, which was stored nearby at an Army ammunition plant where my company was working to eliminate the stockpile in accordance with an international treaty.
VX is, in its chemical structure, a “pesticide.” It would be nice to think pesticides were first created to kill bugs; but no, they were created during the world wars of the last century to kill people, then they were diluted down to create the commercial products spread widely on landscapes today.
So what is this special chemical structure? It has to do with a phosphate bond that creates a certain class of pesticides called “organophosphates.”
Organophosphates
Major players in the organophosphate category include:
Malathion-used on fruit crops apples, apricots, peaches, avocados, citrus; tomatoes, beans, asparagus, barley, corn, and almonds
Chlorpyrifos-sweet corn, soybeans, fruit and nut trees, broccoli, cauliflower, Brussels sprouts, onions
Diazinon – Lettuce, spinach, carrots, basil, cilantro, Brussels sprouts, cantaloupes, beans, and tomatoes, blueberries, cranberries, apples, pears, peaches
Parathion – Banned by the EPA, but formerly used on canola and sunflower crops
Acephate – Approved by EPA for or use on beans, celery, cole crops, cotton, cranberries, mint, non-bearing citrus, peanuts, peppers, soybeans, tobacco
Dimethoate – Potatoes, tomatoes, and leafy or brassica greens, pecans, soybeans, wheat, and fruit trees (citrus and stone fruit, such as cherries)
These pesticides are organic ester derivatives that feature a central phosphorus atom bound to organic groups. They kill pests by blocking the nervous system enzyme acetylcholinesterase. This is the same action VX uses to kill humans, and it is highly effective. One drop of VX on your skin will kill you within minutes. Russians keep a small supply of VX they find handy to use for assassinating people (the international treaty allows them to keep 1 liter). The United States uses its allowed 1 liter to test protective equipment.
Decontamination
Given the cornucopia of chemicals used in agriculture–herbicides, fungicides, as well as pesticides–I like to focus on organophosphates. Deal with organophosphates first, and you’ve dealt with the worst chemicals you have to face.
Household bleach can neutralize many organophosphate pesticides, but it must be used with caution because the reaction can sometimes create temporary byproducts that are more toxic than the original pesticide. More about this below.
Household bleach is alkaline (typically pH 11–13). But it transforms into an acid in water, which breaks down the central phosphate ester bonds, rendering less toxic, water-soluble fragments. The hypochlorite ion acts as a powerful oxidizer, altering the chemical groups attached to the phosphorus atom to make them inactive.
While bleach is highly effective at destroying organophosphates like Malathion, it can initially oxidize certain other organophosphates (such as Chlorpyrifos or Diazinon) into their “oxon” forms (e.g., chlorpyrifos-oxon). These intermediate oxon compounds are more toxic to the nervous system than the original pesticide. That is why it is important to completely rinse the produce after an initial dunk in Dakin solution. The other alternative is to leave the bleach in contact with the pesticide for several hours, and no one wants to do that to their produce!
Disinfection
With the recent outbreaks of Cyclospora, Salmonella, and Listeria, Dakin solution is a must for preventing food-borne illness in your home. All these diseases come in through your door on vegetables.
Many cooking sites recommend baking soda as a way to decontaminate produce. Unfortunately, sodium bicarbonate does not break down phosphate ester bonds. Baking soda does help clean residue on fruits and vegetables, but plain running tap water is equally effective at removing the vast majority of surface dirt, pesticides, and germs. Baking soda does not reliably kill dangerous pathogens like E. coli or Salmonella, like bleach does. Thieves oil is not going to protect us from the genetically engineered biohazards coming our way in this century. Bleach will.
Bleach solution has broad antimicrobial activity against bacteria, fungi, viruses, and parasites. It is even effective against antibiotic-resistant organisms such as MRSA. But the real miracle of Dakin solution is that it eats away damaged flesh while keeping live cells intact. This was especially useful to help heal wounds soldiers suffered during the first world war, when the miracle solution became famous for saving thousands of lives.
Homemade Dakin Solution
By the Great Depression, every household had bleach and knew the formula for Dakin solution. Alas, this knowledge is almost completely lost. I was in the cleaning section of a dollar store during COVID and overheard a couple debating about how to use bleach…straight out of the bottle? A 0.5% solution of off-the-shelf 5.25% bleach, which I’ve seen pre-mixed for customers on Amazon, is too strong. One-tenth of that–0.05 is acceptable or better a fraction of that 0.025 is the concentration limit most hospitals use for wound care, and is sufficient for decontaminating vegetables. The formula I’m giving you is a 1:209 ratio, roughly 0.025 percent.
4 cups water (32 ounces, equal to two pints or a quart)
1 scant teaspoon bleach (plain traditional bleach, not scented or splash-proof, Clorox recommended)
In medical use, a teaspoon of baking soda is added to buffer the solution to avoid skin irritation, a contraindication. I skip this, because Dakin doesn’t irritate my skin, and I want to keep the solution as acidic as possible to help break down any waxes on the fruits and vegetables. If it irritates your skin, you may want to add a teaspoon of baking soda or boric acid.
How to Decontaminate Fruits and Vegetables
It is awkward and a risk to measure a teaspoon out of a bleach bottle. An easy, everyday way to do this is to fill a large stainless steel mixing bowl with three quarts of water and add a capful of bleach, which is about one tablespoon (1 teaspoon X 3). That will give you a 0.025 solution.
That’s it. Easy, peasy. It makes no sense to buy Dakin solution on Amazon that is a concentration recommended for chemical weapon decontamination and blood-spill cleanup. Buy from Amazon if you are a hospital; otherwise, just memorize the Dakin formula and make it at home.
Baking soda decontamination advocates recommend soaking in a sodium bicarbonate solution for 15 minutes. That’s a long time. Dakin solution has an immediate action so you just need to swish the fruits and veggies around for about 10 seconds, then rinse thoroughly under plain running tap water to remove any oxon compounds that might have formed if Diazinon or Chlorpyrifos pesticides were used.
A Good Word for Chlorine
I’ve done my best to convince everyone bleach is not trying to kill us, it’s actually trying to save us. I’m sure my herbal-all-the-way sister-in-law will have none of it. I don’t know why chlorine gets dissed. Perhaps the bad rep came about because it is a promiscuous molecule that easily hooks up with all kinds of atoms, sometimes in unfortunate ways, notably polyamorously, such as polychlorinated biphenyl (PCB). When chlorine settles down with sodium, however, it is a useful, hard-working team player.
Neutrophils of the human immune system produce small amounts of hypochlorous acid inside phagosomes, which are used to digest bacteria and viruses. Your body actually makes sodium hypochlorite. So how could it be so harmful for you?
When rinsing my dishes in Dakin solution I sometimes wonder if that exposure is too much, then I consider Katy Leideke, the Olympic swimmer who trained or competed the distance from Cape Cod, Massachusetts, to Cape Horn, South Africa, in chlorinated water. It doesn’t seem to hurt her: She has 14 gold medals.
For more information on the history, uses, and formulations of Dakin solution, read this article from the National Institutes of Health, National Library of Medicine:
https://www.ncbi.nlm.nih.gov/books/NBK507916/
Keep Everything Clean
One of the most important rules of food safety is to keep everything clean. Wash your hands with soap and warm water for at least 20 seconds before and after handling food, especially raw meat, poultry, seafood, or eggs. Clean countertops, cutting boards, knives, and utensils with hot, soapy water after each use.
Avoid cross-contamination by keeping raw foods separate from ready-to-eat foods. Use separate cutting boards and utensils for raw meat and fresh produce whenever possible. Store raw meat, poultry, and seafood in sealed containers or on the lowest shelf of the refrigerator to prevent juices from dripping onto other foods.
Cooking food to the proper internal temperature is another key step in food safety. Using a food thermometer is the most reliable way to ensure that meat, poultry, seafood, and other cooked dishes have reached a safe temperature. Proper cooking destroys harmful bacteria that can cause illness.
Refrigerate perishable foods promptly. Foods such as meat, dairy products, cooked leftovers, and prepared dishes should not be left at room temperature for more than two hours, or one hour if the temperature is above 90°F (32°C). Keep your refrigerator at or below 40°F (4°C) and your freezer at 0°F (-18°C).
When reheating leftovers, heat them thoroughly until they are steaming hot or reach an internal temperature of 165°F (74°C). Divide large portions into smaller containers before refrigerating to help them cool more quickly and evenly.
Pay attention to expiration dates and signs of spoilage, such as unpleasant odors, mold, or unusual textures. When in doubt about whether a food is safe to eat, it is best to throw it away.
Practicing good food safety habits every day helps reduce the risk of foodborne illness.
Clean as you work, check expiration dates as you use ingredients, and properly store ingredients, and you will have a safe cooking environment in your home.
Beyond the Expiration Date
I emphasize shelf-stable foods on this blog. How long these items really last? The shelf life of pantry and packaged foods varies widely, with low-acid canned goods lasting 2 to 5 years, dried pasta and rice lasting many years (I have an unused bag of rice that is 6 years old and still good to use), and sensitive items like nuts are better off refrigerated, but they will useable several months if kept in a cool, dark place.
I always try to stay within the “best used by” date. However, Martha Stewart claims shelf-stable items can last much longer. Here is her guidance on going past the expiration date:
Canned and Bottled Goods -Low-acid items (meat, beans, vegetables): Peak quality lasts 2 to 5 years past the date.
High-acid items (tomatoes, citrus juices): Peak quality lasts 18 months past the date.
Unopened preserves, pickles, and relishes: Generally last up to 1 year.
Dry Pantry Staples – Dried pasta, rice, and sugar: Indefinite safety, maintaining best quality long past best-by dates.
Dried fruits: Last 6 months to a year at room temperature, or longer sealed in the refrigerator.
Nuts and seeds: High fat content causes rancidity at room temp; store in the fridge for 6 months or freezer for up to 1 to 2 years.
