If you’ve recently started using hypochlorous acid (HOCl) in your skincare routine or as part of your home disinfectant arsenal, you might be wondering: Does it expire? The short answer is yes, hypochlorous acid does expire. But before you toss out that spray bottle, let’s break it down so you understand why, how to tell, and what you can do to make it last longer.
Why Does Hypochlorous Acid Expire?
Hypochlorous acid is a naturally occurring compound with powerful antimicrobial properties, but it’s also a delicate one. Unlike harsher chemicals, HOCl is made using electrolyzed water, salt, and electricity, which makes it environmentally friendly and safe for humans and animals. However, its very nature means it’s not as stable as conventional chemicals like bleach.
Over time, exposure to air, heat, light, and even the material of the container can degrade the hypochlorous acid into ordinary saltwater. This reduces its effectiveness, which is why using it past its prime won’t give you the results you expect, whether you’re using it to clean wounds, treat acne, or sanitize surfaces.
How Long Does Hypochlorous Acid Last?
The shelf life of hypochlorous acid depends on how it’s produced and stored.
Commercial Products: Most commercially produced HOCl solutions are stabilized to last between 6 to 12 months if unopened. Once opened, the clock starts ticking faster, and you may have only a few months before its potency begins to decline.
How to Tell If Hypochlorous Acid Has Expired
Unfortunately, there’s no dramatic color change or foul smell to indicate that your HOCl has expired. Instead, its antimicrobial effectiveness quietly diminishes. Here are some signs:
It doesn’t work as well. If you’re using it to clean or disinfect and notice lingering odors or slower healing of wounds, it might no longer be active.
You’ve had it for a while. If you can’t remember when you bought or made it, it’s safer to assume it’s no longer effective.
Overall, if it has been over a year of having the HOCl spray, you can assume it may be expired and time to purchase a new one.
How to Extend the Shelf Life of Hypochlorous Acid
To make the most of your HOCl solution, follow these tips:
Store It in a Cool & Dark Place: Heat and light are key players that degrade hypochlorous acid. Keep it in a cabinet or pantry and away from direct sunlight.
When purchasing a HOCl spray in the market, make sure it is a brand that includes manufacturing date and expiration date on the package (like ours at Honeydew Labs!)
Use Proper Containers: Always store HOCl in opaque, airtight containers made from plastic or glass. Metal containers can react with the solution and cause degradation.
Check the pH: The pH of HOCl should be around 5.5 to 6.5 for optimal effectiveness. If you have a pH meter, test it periodically to ensure it hasn’t shifted.
Don’t Open and Contaminate It: Avoid opening the bottle and letting it interact with air. Also dipping dirty cloths or hands into the bottle, as introducing contaminants can speed up its breakdown.
When in Doubt, Replace It
As much as we love hypochlorous acid for its versatility and gentleness, it’s not meant to last forever. If you’re unsure whether your HOCl solution is still good, it’s best to replace it. Using an expired solution might not harm you, but it also won’t give you the benefits you’re looking for—whether that’s clear skin, clean surfaces, or soothed irritations.
Why Our Hypochlorous Acid Spray Stands Out
Not all hypochlorous acid sprays are created equal, but we’ve made ours to be as effective and gentle as possible. It has the manufacturing date and expiration date straight on the packaging so you don't have to guess!
The best part? It’s available on Amazon Canada or Amazon USA, so you can order it in just a couple of clicks. If you’re curious about HOCl and want to give it a try, this is the spray to start with.
Overall Thoughts:
Yes, hypochlorous acid does expire, but with proper storage and a little attention to detail, you can maximize its shelf life. Whether you’re using it for skincare or as a disinfectant, always keep an eye on how long you’ve had it and how it’s stored. Remember, a fresh and active solution is the key to getting the most out of this powerful yet gentle ingredient.
Using hypochlorous acid for skincare and worried if hypochlorous acid can cause purging? Learn more now!
Disclaimer: For Honeydew Lab products, always check the box for specific storage instructions and expiration details.
References:
Landa-Solis, C., Gonzalez-Espinosa, D., Guzman-Soriano, B., Snyder, M., Reyes-Teran, G., & Torres, K. (2005). Stability and antimicrobial activity of super-oxidized water with neutral pH. Journal of Hospital Infection, 61(4), 291–299.
Discusses the stability and degradation of HOCl under different storage conditions.
Horiba, N., Hiratsuka, K., Onoe, T., Yoshida, T., Suzuki, K., Matsumoto, T., & Nakamura, H. (1999). Stability of electrolyzed water with reference to disinfective property. Journal of Antimicrobial Chemotherapy, 47(3), 435–440.
Explores the factors that affect the shelf life of electrolyzed HOCl solutions.
Wang, L., Bassiri, M., Najafi, R., Najafi, K., Yang, J., Khosrovi, B., … & Benforado, K. (2007). Hypochlorous acid as a potential wound care agent. Journal of Burns and Wounds, 6, e4.
Provides insights into the stability of HOCl when used in medical settings.