Hypochlorous Acid for Eyelid Hygiene: Science, Safety, and What Brands Need to Know

Contents

1.  What Is Hypochlorous Acid?
2.  Why Eyelid Hygiene Is a Growing Personal Care Priority
3.  How HOCl Works on the Eyelid
4.  Not All HOCl Is the Same
5.  The Regulatory Landscape for HOCl Eyelid Products
6.  Why Brands Choose Aqualution
7.  The Market Opportunity
8.  Frequently Asked Questions

1.  What Is Hypochlorous Acid?

Hypochlorous acid (HOCl) is a weak acid and powerful natural antimicrobial. It is produced endogenously by the human immune system – specifically by neutrophils (white blood cells) during a process called the oxidative burst – as a first-line defence against bacteria, viruses, and fungi.

In topical applications, HOCl is produced synthetically via electrolysis: an electrical current is passed through a solution of water and salt, generating a stabilised HOCl solution that replicates the molecule’s natural chemistry. When produced correctly – at sufficient purity and with verified stability – the result is a substance that can eliminate a broad spectrum of pathogens without the toxicity, irritation, or antimicrobial resistance risk associated with conventional disinfectants.

The key distinction is in production method. Most HOCl on the market is made by acidifying bleach – a fundamentally different and inherently less stable process that produces a molecule with a significantly shorter real-world shelf life than its label states. Aqualution’s HOCl is produced exclusively via proprietary electrolysis – the method that produces the molecule at its highest attainable purity and stability.

2.  Why Eyelid Hygiene Is a Growing Personal Care Priority

The eyelid margin is one of the most microbiologically active environments on the body. A dense film of bacteria, skin debris, exfoliated cells, and disrupted lipids accumulates along it daily. Without regular, effective cleansing, this accumulation can contribute to discomfort and conditions that optometrists and ophthalmologists increasingly encounter.

Blepharitis

Blepharitis – chronic inflammation of the eyelid margins – is among the most common concerns seen in optometric and ophthalmic practice. It is associated with Staphylococcal overgrowth, Demodex mite infestation, and seborrhoeic dermatitis. For individuals experiencing this condition, maintaining a clean eyelid margin is an important part of daily personal care. Conventional cleansing approaches, including diluted baby shampoo or surfactant wipes, can be irritating to periocular tissue and may not effectively reduce microbial load.

Meibomian Gland Dysfunction

Meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye. The meibomian glands produce the lipid layer of the tear film; when obstructed or inflamed – often in the context of microbial overgrowth along the lid margin – the tear film can destabilise. For individuals managing this condition, regular eyelid hygiene to reduce microbial burden on the lid margin is a commonly recommended personal care practice.

Dry Eye and General Periocular Comfort

Dry eye affects a substantial and growing proportion of the population, driven by increasing screen time, ageing demographics, air-conditioned environments, and contact lens wear. The periocular microbiome plays a significant but often underappreciated role in tear film stability. Many individuals who experience periocular discomfort incorporate regular eyelid cleansing into their daily routine as a matter of general eye hygiene.

Across all three areas, the direction is the same: away from harsh, detergent-based approaches and towards biocompatible, gentle antimicrobial solutions. HOCl’s safety profile and efficacy as a cleansing agent make it well suited to this role.

3.  How HOCl Works on the Eyelid

HOCl exerts its antimicrobial effect by disrupting microbial cell membranes and denaturing proteins essential to pathogen survival. Its mechanism of action is broad-spectrum: it is effective against gram-positive and gram-negative bacteria (including Staphylococcus aureus and Pseudomonas aeruginosa), enveloped and non-enveloped viruses, fungi, and Demodex mites – the range of organisms commonly found on the eyelid margin.

Critically, HOCl achieves this without the toxicity to human tissue associated with conventional antiseptics. At the concentrations used in topical eyelid applications, it does not damage healthy epithelial cells, disrupt the tear film, or cause sensitisation. It does not contribute to antimicrobial resistance, because its mechanism of action is non-selective oxidation rather than a targeted molecular pathway that organisms can evolve around.

Additional properties relevant to eyelid formulations:

4.  Not All HOCl Is the Same

The HOCl market contains a significant volume of inferior product – and nowhere is the quality gap more consequential than in eyelid applications. The periocular environment is sensitive, the user population often includes those with already-compromised tissue, and regulatory scrutiny of eyelid hygiene products is increasing.

The production method is the primary quality determinant. Acidifying bleach – the most common production method in the market – generates a molecule that is chemically similar in name but fundamentally different in stability. HOCl produced this way degrades rapidly and unpredictably: the concentration at point of use is often significantly lower than the stated label concentration, and the real shelf life is a fraction of what is claimed.

Aqualution’s HOCl is produced via proprietary electrolysis. This is not a marginal improvement – it is a structurally different product.

The difference is not marginal. It is the difference between a label claim you can defend and one you cannot – and in the eyelid hygiene market, that distinction has regulatory and commercial consequences.

5.  The Regulatory Landscape for HOCl Eyelid Products

Brands developing HOCl eyelid hygiene products face an important and consequential classification decision at the outset. The regulatory pathway determines everything downstream: formulation, testing requirements, technical documentation, labelling, and the claims you can make. There are three primary pathways to consider.

Cosmetic Classification

A product positioned around cleansing, soothing, or maintaining the condition of eyelid and periocular skin – without making therapeutic or medicinal claims – will typically be classified as a cosmetic under the UK Cosmetic Products Regulation and EU Regulation (EC) No 1223/2009. This route requires a Cosmetic Product Safety Report (CPSR), a Product Information File (PIF), and a Responsible Person (RP) registered in the relevant market. This is the most common and most accessible pathway for brands entering the eyelid hygiene category.

Medical Device Classification

A product making claims related to the prevention, management, or treatment of specific conditions will almost certainly be classified as a medical device under UK MDR 2002 (as amended) and EU MDR 2017/745. This is a demanding and expensive route: it requires conformity assessment, CE or UKCA marking, a Quality Management System certified to ISO 13485, and robust clinical evidence. The technical and financial burden is significant, and timelines are considerably longer than the cosmetic pathway.

It is worth noting that a medical device eyelid hygiene product does not have to make therapeutic claims. An HOCl eyelid hygiene product can be CE marked as a medical device while making only cleansing and hygiene claims – effectively the same claims as a cosmetic, but supported by the additional rigour of the medical device framework. For brands for whom the CE mark carries commercial value with retail or professional buyers, this may justify the investment.

Biocide Classification (selected jurisdictions)

In some jurisdictions, an eyelid hygiene product could be classified as a biocide rather than a cosmetic or medical device, depending on the primary function claimed and the regulatory framework applied. In the UK and EU, biocidal products are governed by the UK Biocidal Products Regulation (retained from EU BPR 528/2012). Where a product’s primary function is antimicrobial action, a Product Type 1 (PT1) biocide authorisation – covering human hygiene biocidal products – may be the appropriate route.

This pathway is only relevant in specific jurisdictions and circumstances, and requires the active substance (HOCl) to be listed on the Article 95 active substance list for the relevant product type. Aqualution is on the relevant Article 95 lists for the UK and EU. For brands considering this route, specialist regulatory advice for the specific target market is essential.

Ask any HOCl supplier whether they are listed on the UK and EU Article 95 active substance lists for HOCl. If they are not, they cannot legally support biocidal label claims in those markets – regardless of what their product literature says.

Aqualution also holds ISO 13485 QMS certification – the quality management standard required for medical device supply chains – and can provide regulatory guidance across all three pathways for brands entering this market.

6.  Why Brands Choose Aqualution

Eyelid hygiene is not a new application area for Aqualution. Our HOCl has been used in aesthetic and eye care product development contexts, including commercial eye care product development in the US market.

For brands entering this category, the application development work has already been done. Formulation, stability testing, packaging compatibility, and scale-up to commercial production are not starting-point questions with us – they are resolved. For brands considering a medical device pathway, we can provide classification guidance and signposting to the appropriate regulatory framework – a route we recognise is technically demanding and carries significant investment requirements. We also provide Responsible Person support for cosmetic PIFs.

We do not manage accounts. We develop applications – working with brand owners who need a manufacturing partner they can defend to regulators, retailers, and consumers alike.

7.  The Market Opportunity

The conditions driving demand for HOCl eyelid hygiene products – blepharitis, dry eye, meibomian gland dysfunction – are not going away. Ageing populations, increasing screen time, greater awareness of eye health, and a consumer shift toward biocompatible, evidence-backed personal care solutions are all structural tailwinds for this category.

Cosmetics regulation and ingredient transparency are tightening globally. Retailer audits are more rigorous. The evidence behind a label claim is no longer a back-office concern – it is a listing requirement. Brands that enter this market with a well-credentialled manufacturing partner are positioned to lead.

HOCl sits at the intersection of antimicrobial efficacy and cosmetic acceptability. As a molecule, it is suited to this space. As a manufacturing category, it rewards the brands that chose the right partner from the outset.