Industry-First*¹: Gaseous Hypochlorous Acid Suppresses Over 99% of Adhered Pertussis Bacteria*²

Osaka, Japan – Panasonic Corporation (https://holdings.panasonic/global/) today announced that its Heating & Ventilation A/C Company (hereinafter referred to as Panasonic) became the industry-first*¹ to confirm that gaseous hypochlorous acid—an active chlorine component volatilized from hypochlorous acid solution*³—suppresses over 99% of adhered pertussis bacteria within 4 hours*².

Pertussis, caused by the pertussis bacterium, is a highly contagious acute respiratory infection characterized by spasmodic coughing fits. While infants are particularly vulnerable and may develop severe symptoms, recent trends show a notable increase in cases among teenagers*⁴. This has raised concerns about the spread of infection not only in households and childcare facilities with frequent contact with infants, but also in densely populated environments such as schools where teenagers are highly active. In 2025, pertussis, COVID-19, fifth disease (erythema infectiosum), and measles simultaneously spread, drawing significant public attention and leading to the coining of the term “Quattro Infectious Diseases.”

The hypochlorous acid solution is produced through the electrolysis of salt water and demonstrates high efficacy in sterilization and deodorization. Since adopting the hypochlorous acid solution for the hygiene maintenance system of cup-dispensing vending machines in 1987, Panasonic has been researching hypochlorous acid technology for approximately 40 years*⁵. Our verification using hypochlorous acid solution has been conducted in a space of approximately 25 m³ (about 6 tatami mats), in accordance with The Japan Electrical Manufacturers’ Association Standard (JEM1467), which is commonly used for evaluating the performance of air purifiers—even in basic research. This is due to the characteristic of gaseous hypochlorous acid, volatilized from the solution, which resists self-decomposition and diffuses over long distances*⁶. To date, Panasonic has confirmed its suppressive effects on the novel coronavirus (SARS-CoV-2) omicron variant, canine parvovirus, and the measles virus. With the newly confirmed effectiveness against pertussis bacteria, gaseous hypochlorous acid is now expected to suppress all four pathogens responsible for the so-called “Quattro Infectious Diseases.”*⁷

Panasonic will continue to advance hypochlorous acid technology and pursue its full potential to contribute to society through providing safe and secure environments.

*1: In Japan's air purification and air conditioning industry. As of October 31, 2025, according to Panasonic's research.
*2: These verifications were conducted for basic research purposes and did not involve any products containing the hypochlorous acid solution.
*3: Solution made by electrolysis of salt water.
*4: Source: Japan Institute for Health Security (https://www.mhlw.go.jp/stf/seisakunitsuite/bunya/kenkou/kekkaku-kansenshou19/whooping_cough.html)
*5: Including SANYO Electric Co. Ltd.
*6: The half-life of gaseous hypochlorous acid—the time it takes for its concentration to reduce by half—is over 50 hours (based on our research), which is more than 2.5 times longer than ozone, known for its disinfecting and deodorizing effects, whose half-life is approximately 20 hours.
Source: “Actual Ozone Utilization Purification Technology” published by Sanyu Shobo.
*7: Canine parvovirus is substitute virus for human parvovirus, the causative agent of fifth disease (erythema infectiosum).
Source: WHO Technical Report, Series No. 924 Annex 4, 2004

Hypochlorous acid is a well-established and historically proven disinfectant, commonly used for chlorination in tap water. It is a powerful oxidizing agent that sterilizes and deodorizes by oxidizing—suppressing the activity of—bacteria and odors through electron removal. Among hypochlorous acid molecules (HOCl), the Cl+ ion exerts strong oxidative decomposition power by stealing electrons from other substances.
Hypochlorous acid solution is generated by electrolyzing saline water. The gaseous hypochlorous acid volatilized from the solution has a half-life of over 50 hours, making it highly resistant to self-decomposition and capable of diffusing over long distances.

●Verifying organization: Panasonic Corporation
Testing organization: Kitasato Research Center for Environmental Science
●Verification device: The rotary filter was soaked in a hypochlorous acid solution of approx. 100 mg/L and was exposed to a specified amount of wind (3.8 m³/min) to volatilize the active chloride component.
●Verification method
• Exposure time: 0 to 12 hours
• Test space volume
Exposure: Approx. 25 m³ (about 6 tatami mats), no ventilation, with verification equipment
Non-exposure (natural attenuation): Approx. 25 m³ (about 6 tatami mats), no ventilation, no verification equipment
• Placement of pertussis bacteria
Exposure: Drop specified amount of liquid containing pertussis bacteria onto a petri dish in five designated spots (2 μL each, totaling 10 μL), and dry for approx. 60 minutes inside a biosafety cabinet. Place pertussis bacteria-attached samples 1.5 m away from the verification device (1.2 m above the floor).
Non-exposure: Place pertussis bacteria-attached samples inside a test chamber of approx. 25 m³ (about 6 tatami mats)
• Exposure method
Operate the verification device.
• Measurement of pertussis bacteria
Collect petri dishes at each predetermined time. Use the washout liquid from the dishes as an undiluted test solution and serially dilute it to 10 levels using sterile physiological saline. Apply 0.1 mL of either the undiluted test solution or each dilution to sheep blood agar plates. Incubate the plates at 37 ± 2°C for 7 days. After incubation, count the grown colonies and determine the number of adhered bacteria per petri dish.

●Verification result: confirm that gaseous hypochlorous acid suppresses over 99% of adhered pertussis bacteria within 4 hours. (Figure 1)