The Hidden Variable in Hand Hygiene: Why Dose Size, Standards, and Technology Matter

Hand hygiene remains the cornerstone of infection prevention, but the conversation often stops at when to clean hands rather than how much product is needed. For infection preventionists (IPs) and health care leaders, overlooking the critical factor of dose size risks undermining adherence, workflow, and ultimately, patient safety.

To clarify some details around hand hygiene, dose size, and standards, Infection Control Today^® interviewed James W. Arbogast, PhD, hand hygiene expert and scientific consultant for SC Johnson Professional. Arbogast has been directly involved in the formulation and launch of numerous products in the laundry, air freshening, hair care, skin care, surface cleaners/disinfectants, and hand hygiene markets. He has over 30 years of experience in consumer product development, with the last 25 years focused on skin care and hand hygiene.

Hand Hygiene as a Cornerstone

“Hand hygiene is one of the cornerstones of infection prevention and control in health care settings,” Arbogast explains. “Ensuring hands are clean is critical in these settings, as contaminated hands can facilitate cross-contamination between patients, surfaces, and medical equipment, contributing directly to health care–associated infections.”

The “chain of infection” reminds us how quickly pathogens move from reservoirs to susceptible hosts. A health care worker who skips proper sanitization—or uses too little sanitizer—can inadvertently become a link in this chain. “This chain includes the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. In clinical environments, health care workers may inadvertently become a link in this chain, especially during patient care activities such as physical examinations or handling of shared equipment if proper hand hygiene is not maintained,” Arbogast notes.

Hand Sanitizers Can Increase Hand Hygiene Adherence

“Hand sanitizers are a fast, effective, and skin-friendly way to improve hand hygiene,” Arbogast says. “Because they can be placed in more locations, such as outside and inside patient rooms, hand sanitizers [are] a key component of hand hygiene adherence.”

Arbogast explains that hand sanitizers typically kill a broad spectrum of germs in 20 to 30 seconds, whereas traditional handwashing usually takes 40 to 80 seconds to reduce germs effectively.¹ For health care workers constantly on the go, ensuring proper hand cleanliness, even when handwashing stations are not as readily available, makes alcohol-based hand sanitizer an essential tool in infection control.^2,3

Why Dose Size Matters

“Many people assume a quick squirt of sanitizer is enough,” notes Arbogast, but that assumption carries risk. “Using too little product, or less than 1.5 mL, can leave approximately 5% to 10% of the hand surface untreated, allowing germs to potentially survive and spread through the hands of health care personnel in contact with patients, equipment, or the environment.”⁴

Arbogast explained that thumbs and fingertips are often overlooked as the main contact points with people and surfaces. Using too little hand sanitizer can create a false sense of cleanliness, allowing too many infectious germs to remain and spread unknowingly throughout the environment.

The Leapfrog Group recommends that sanitizer remain wet for at least 15 seconds, while the CDC and World Health Organization recommend that it be closer to 20 seconds. The product must cover all surfaces and stay wet long enough to kill pathogens. Too small a dose dries too quickly; too large a dose (e.g., 2 mL or more) may extend drying time past 30 seconds, discouraging staff from completing the process.

Technology such as SC Johnson Professional’s OPTIDOSE™, which delivers 1.5 mL of product, when used correctly, can help ensure peace of mind for facilities and staff. A single dose from an OPTIDOSE™ pump provides enough foaming hand sanitizer to keep hands wet for 20 to 30 seconds for all healthcare personnel, which aligns with WHO and Leapfrog Group recommendations.

Aligning Dose With the 5 Moments

The WHO’s 5 Moments for Hand Hygiene⁵ remains the best practice framework for training and observation around when to clean hands:

1. Before touching a patient
2. Before clean/aseptic procedures
3. After body fluid exposure risk
4. After touching a patient
5. After touching patient surroundings

Arbogast underscores how correct dosing links to these key moments: “Correct hand sanitizer use is especially critical during Moments 1 and 2, which focus on protecting the patient from health care–associated infections. Moments 3, 4, and 5 are primarily about protecting health care workers and preventing environmental contamination post patient care.”

The key insight is that it is not enough for health care workers to merely comply with the when. The how much ensures that adherence is protective.

Testing Methods That Matter

Selecting products with proven efficacy means going beyond marketing claims. IPs should look for products validated through in vivo methods.^6-8

Arbogast highlighted the following validated in vivo standard protocols:

• EN 1500: Tests alcohol-based hand rubs using 1.5 mL of product compared with a reference control
• ASTM E2755: Mimics real-world contamination by dry bacteria transfer to optimally test hand sanitizers
• EN 1499/ASTM E1174: Evaluates handwash efficacy with heavy soil, better suited for soap and water-based hand hygiene

“Using these standards to evaluate the optimal dose size is critical to ensure products are proven to be effective at reducing the number of common germs on hands to help prevent the spread of infection,” Arbogast states. “It is also important that infection preventionists ensure that dispensers dose the proper amount of hand sanitizer every time to trust that all health care workers receive an efficacious volume of product.”

For IPs, this means asking vendors whether their products passed EN 1500 &/or ASTM E2755, and at what dose. A sanitizer that only meets benchmarks at 3 mL may not be practical in busy units.^6-8

Technology That Makes Technique Visible

Even with the correct dose and timing, the technique often falters. Staff may miss thumbs, fingertips, or dorsal surfaces. How can IPs make the invisible visible?

One promising tool is thermal imaging, featured in an Infection Control Today interview with John Boyce, MD, one of the authors of the original WHO 5 Moments for Hand Hygiene.^5,9 During the interview, Boyce explained that thermal cameras visualize alcohol evaporation, revealing where sanitizer coverage is incomplete. “Thermal imaging provides a quick, noninvasive way to show health care workers in real time whether they achieved full coverage, making [adherence] not just a checkbox but a visible outcome,” Boyce noted.

By pairing thermal imaging spot-checks with routine audits, IPs can:

• Reinforce technique during onboarding and retraining
• Provide immediate, nonpunitive feedback
• Align dose, rub time, and coverage with evidence-based standards

This technology does not replace direct observation but strengthens it by turning adherence into a tangible, teachable skill.

Practical Product Selection

When evaluating new hand hygiene products, Arbogast advises: “IPs should look at real-world in vivo efficacy data. The best evidence comes from testing using validated methods like EN 1500 or ASTM E2755, which show how well hand sanitizer products kill germs in conditions that mimic clinical use.”

If health care personnel find hand sanitizer products to be uncomfortable in any way, they will avoid them. “Skin compatibility is also a key factor to consider,” Arbogast says. “Products should be antimicrobially effective without causing irritation or allergic reactions. Hand sanitizer products should kill many common germs quickly and not damage skin, especially when used frequently.”

Trialing products with frontline staff is essential, considering user acceptability (comfort, smell, stickiness) and tolerability (skin condition). Poor user experience reduces adherence, even with a proven product.

“Finally, it’s also important to trial hand sanitizer products for acceptability (user liking) and tolerability (skin condition) by health care workers. When trialing, staff should find the product comfortable to use and not experience issues like stickiness, irritation, or dryness, which can reduce usage and compliance. The best way to judge adherence is around the ‘5 Moments for Hand Hygiene’ or, in the US, the ‘in and out’ standard assessed by The Joint Commission, which tracks how often staff clean their hands when entering and exiting patient rooms,” Arbogast says.

The Key Message

If there is one takeaway for IPs, Arbogast says it is this: “Don’t assume all hand sanitizers are the same and any dose size is sufficient. IPs and health care leaders should educate staff on the correct volume of alcohol-based hand sanitizer and the time needed for it to work effectively.”

The 2022 SHEA/IDSA/APIC practice recommendation, updated in 2023, echoed this call for precise dosing and contact time guidance.⁹ Arbogast states, “Not all sanitizers or hand washes are the same. Ingredients and formulation impact both efficacy and user experience. Poor user experience will lead to lower adherence. That’s why it’s important to request and review testing data from manufacturers and trial products for acceptability and tolerability.”

A Call to Action for Infection Prevention Leaders

1. Demand data: Require EN 1500/ASTM E2755 hand sanitizer testing reports at realistic dosing from experienced contracted clinical labs.
2. Standardize outputs + Audit the dose: Don’t just track “in/out.” Measure dispenser volume to ensure consistent delivery of 1.5 mL per pump stroke, wet time, and coverage.
3. Leverage technology: Use thermal imaging to make invisible technique gaps visible.
4. Educate relentlessly: Tie dosing guidance to the 5 Moments and reinforce with feedback.

Conclusion

Hand hygiene adherence is not simply about frequency. It is about the right product, dose, moment, and technique—all validated by robust testing and supported by innovative training tools.

As Arbogast emphasizes: “The key message is to remember to get the data, test the product, and make sure staff know how to use it correctly.”

For IPs and influencers, that means elevating dose size from an afterthought to a frontline metric. When paired with technology such as thermal imaging and aligned with international standards, dose awareness can transform adherence from a box to tick into a reliable barrier against health care–associated infections.

References

1. Voss A, Widmer AF. No time for handwashing!? handwashing versus alcoholic rub: can we afford 100% compliance? Infect Control Hosp Epidemiol. 1997;18(3):205-208. doi:10.1086/647590
2. Pittet D, Hugonnet S, Harbarth S, et al. Effectiveness of a hospital-wide programme to improve compliance with hand hygiene: infection control programme. Lancet. 2000;356(9238):1307-1312. doi:10.1016/s0140-6736(00)02814-2
3. Arbogast JW et al. Hand hygiene patterns in 38 North American hospitals captured by automated hand hygiene monitoring. Presented at: Society for Healthcare Epidemiology of America Spring Conference; April 18-20, 2018; Portland, OR.
4. Voniatis C et. A large-scale investigation of alcohol-based handrub (ABHR) volume: hand coverage correlations utilizing an innovative quantitative evaluation system. Antimicrob Resist Infect Control. 2021;10, 49. https://doi.org/10.1186/s13756-021-00917-8
5. Five moments for hand hygiene. World Health Organization. Accessed September 2025. https://www.who.int/publications/m/item/five-moments-for-hand-hygiene
6. Macinga DR, Beausoleil CM, Campbell E, et al. Quest for a realistic in vivo test method for antimicrobial hand-rub agents: introduction of a low-volume hand contamination procedure. Appl Environ Microbiol. 2011;77(24):8588-8594.doi:10.1128/AEM.06134-11
7. ASTM E2755-22: standard test method for determining the bacteria-eliminating effectiveness of healthcare personnel hand rub formulations using hands of adults. ASTM International. https://store.astm.org/e2755-22.html
8. Glowicz JB, Landon E, Sickbert-Bennett EE, et al. SHEA/IDSA/APIC practice recommendation: strategies to prevent healthcare-associated infections through hand hygiene: 2022 update. Infect Control Hosp Epidemiol. 2023;44(3):355-365. doi:10.1017/ice.2022.304
9. Whitacre Martonicz T. Increasing hand hygiene adherence with thermal imaging. Infection Control Today. October 14, 2022. Accessed September 5, 2025. https://www.infectioncontroltoday.com/view/thermal-imaging-to-increase-hand-hygiene-adherence