SOS Daily Rescue Facial Spray and hypochlorous acid: what a face mist can and can't do
Most face mists are water with a little glycerin and fragrance. The SOS Daily Rescue Facial Spray, from the US brand Tower 28, is different in one way that explains its popularity: its ingredient list has only three entries, and one of them is hypochlorous acid, a molecule your own immune system makes. This guide explains what hypochlorous acid is, what the evidence supports, and where a spray stops being useful.
- Published ingredients: water, sodium chloride, hypochlorous acid. No fragrance, no alcohol. The brand gives a pH of 4.5.
- Hypochlorous acid (HOCl) is a mild oxidant made by white blood cells to kill microbes. Stabilized solutions are used in medicine for wound and scar care.
- Evidence for cosmetic use (redness, breakouts, irritation) is promising but limited, and depends heavily on how a given product is stabilized.
- A mist does not replace a cleanser, a moisturizer, an acne treatment or sunscreen.
How this guide was written: no product testing and no reviews. The ingredient list, pH and the brand's statements are taken from its own product page (accessed October 2026); the science comes from the peer-reviewed sources listed at the end.
What the label says
- Water
- Sodium Chloride
- Hypochlorous Acid
Three ingredients is about as short as a cosmetic list gets. Sodium chloride is ordinary salt: hypochlorous acid is commonly produced by passing an electric current through salt water (electrolysis), and some salt remains. There is no preservative listed because hypochlorous acid is itself antimicrobial. There is also no added fragrance, which matters for sensitive skin, since fragrance is one of the most common causes of cosmetic allergy.
The brand states that its chemists spent eight years stabilizing the formula before launch, and that the spray carries the US National Eczema Association's Seal of Acceptance. Those are the brand's claims; we report them, we have not verified the eight years.
What hypochlorous acid is
When neutrophils, a type of white blood cell, meet bacteria, they produce hypochlorous acid as part of what immunologists call the oxidative burst. It is the same active species as in diluted bleach, but at a very different concentration and pH: in a weakly acidic solution, the chlorine is mostly present as hypochlorous acid rather than the harsher hypochlorite ion found in household bleach. That pH balance is one reason product pH matters.
The difficulty is stability. Hypochlorous acid breaks down with light, heat, air and contact with organic matter, which is why it was used for decades in hospitals but rarely in shelf products. Newer manufacturing methods produce solutions that stay stable for longer in sealed, opaque packaging.
What the evidence supports
- Wound and scar care. A panel of clinicians led by Gold and colleagues (2020, Journal of Cosmetic Dermatology) reviewed stabilized hypochlorous acid in procedures and described it as active against bacterial biofilms and useful in wound and scar management. This is the strongest body of use, and it is medical rather than cosmetic.
- Inflammatory skin conditions. Del Rosso and Bhatia (2018, Journal of Clinical and Aesthetic Dermatology) reviewed antimicrobial, anti-itch and anti-inflammatory properties and possible roles in conditions such as atopic dermatitis. Their review focused on one prescription formulation, and the authors had industry ties; it supports interest, not certainty.
- Acne and redness. Dermatologists use hypochlorous products off-label as gentle adjuncts. There are few controlled trials of over-the-counter mists for acne. It is not a substitute for proven acne treatments such as benzoyl peroxide, salicylic acid or adapalene (see our acne-prone skin routine).
Studies on one stabilized solution don't automatically apply to another. Concentration, pH, salt content and packaging all change how much active hypochlorous acid reaches your skin, and none of the cosmetic mists on the market publish their concentration in parts per million on the box.
What a mist can't do
- It doesn't moisturize. Water evaporates. Without a humectant or a cream on top, a mist can leave skin feeling drier, especially in air-conditioned rooms. Follow with moisturizer.
- It doesn't clean. Sunscreen, sebum and pollution particles need a cleanser. See pollution and skin.
- It doesn't set or replace sunscreen. The brand itself says it is not a makeup setting spray, and it has no SPF.
- It doesn't treat infection. A hot, painful, spreading or weeping area of skin needs a doctor, not a spray.
How to use a hypochlorous mist
- After cleansing, spray a few times on the face from arm's length, eyes closed.
- Let it dry for a minute, or pat it in.
- Continue your routine: serum, moisturizer, and in the morning sunscreen. It layers easily under a hyaluronic acid serum.
- During the day, some people use it after exercise or a sweaty commute when they cannot wash. That is reasonable, but it does not replace an evening cleanse.
The brand advises separating it from vitamin C serums. As a general rule, hypochlorous acid is an oxidant and vitamin C (ascorbic acid) is an antioxidant: applied together, each can use up the other. Use them at different times of day.
Storage
Keep the bottle closed, out of direct sun and away from heat. Hypochlorous acid is one of the ingredients most sensitive to the conditions described in our guide to storing skincare in heat and humidity; a mist left in a hot car or on a sunny windowsill in the tropics is unlikely to keep its strength until the expiry date.
| Type | Typical ingredients | What it does |
|---|---|---|
| Hypochlorous mist | Water, salt, hypochlorous acid | Mild antimicrobial, may calm irritation |
| Hydrating mist | Water, glycerin, hyaluronic acid | Brief hydration; needs moisturizer on top |
| Thermal water | Mineral spring water | Cooling, soothing feel |
| Setting spray | Water, film-forming polymers, alcohol | Holds makeup; not skincare |
Sources
- Ingredient list, pH, stabilization and seal statements as published on the brand's product page for SOS Daily Rescue Facial Spray (accessed October 2026).
- Gold M.H. et al., "Topical stabilized hypochlorous acid: The future gold standard for wound care and scar management in dermatologic and plastic surgery procedures", J Cosmet Dermatol 2020;19(2):270–277.
- Del Rosso J.Q., Bhatia N., "Status Report on Topical Hypochlorous Acid: Clinical Relevance of Specific Formulations, Potential Modes of Action, and Study Outcomes", J Clin Aesthet Dermatol 2018;11(11):36–39.
- American Academy of Dermatology, Acne: tips for managing.
Routines by skin typeA routine for sensitive skin
Stinging, redness and reactions: a minimal routine, the usual suspects on labels, and when it isn't 'just sensitive'.
Routines by skin typeOily and acne-prone skin
Benzoyl peroxide, salicylic acid and adapalene, used gently, with a light moisturizer and daily sunscreen.
Climate and relocationPollution and skin
Fine particles, traffic soot, ozone and UV: what studies link to skin, and why 'anti-pollution' claims need care.