Ozone Concentration and Its Effects Safe Ozone Levels The maximum safe ozone concentration for human exposure is generally set at 0.2 mg/m³. According to industrial hygiene standards, different countries have their own guidelines: International Ozone Association: 0.1 ppm for 10 hours of contact United States: 0.1 ppm for 8 hours of exposure Germany, France, Japan: 0.1 ppm China: 0.15 ppm For household ozone disinfection cabinets, the leakage must not exceed 0.2 mg/m³ at a height of 1.5 meters. The residual ozone after one cycle should also stay below this level. Animal studies suggest that the toxic threshold starts at 0.3 ppm, while humans can detect ozone at concentrations as low as 0.02–0.04 ppm. Based on pulmonary toxicity tests, the upper limit for acceptable ozone concentration is around 1.5–2.0 ppm. The Ministry of Health sets the maximum allowable concentration at 0.2 mg/m³. Ozone Application in Air For air deodorization and sterilization, ozone levels are typically kept low—around 0.5 ppm (1 mg/m³). For surface disinfection, higher concentrations may be needed, often tens of times more. The recommended range for air applications is between 1 mg/m³ and 10 mg/m³. Humidity plays a significant role: when relative humidity is below 45%, ozone has minimal effectiveness against airborne microbes. However, at 60% humidity, its efficacy increases, peaking at 95%. In food processing plants, 0.5–1.0 ppm of ozone can kill about 80% of natural bacteria in the air. Cold storage requires 6–10 ppm of ozone, achieving up to 90% bacterial reduction and 80% mold control after shutdown. In fruit storage, 2–3 ppm of ozone can double the shelf life by inhibiting mold growth. Ozone Application in Water Ozone solubility in water ranges from 0.1 mg/L to 10 mg/L. The lower end represents the minimum required for water purification, while the higher value is typical for ozonated water. International standards for tap water treatment usually recommend a solubility of 0.4 mg/L, with a CT value of 1.6 (0.4 mg/L × 4 minutes). For effective disinfection, ozone concentration should remain between 0.1–0.5 mg/L for 5–10 minutes. Ozone acts quickly in water, killing bacteria within 0.5–1 minute at 4 mg/L. At 0.43 mg/L, E. coli is fully eliminated at 20°C, while at 10°C, only 0.36 mg/L is needed. Hepatitis A virus (HAV) is inactivated within seconds to minutes at concentrations between 0.25–38 mg/L. In mineral water, 0.4–0.5 mg/L of dissolved ozone meets sterilization requirements, with an optimal dose of 1.5–2.0 mg/L. For bottled water treatment, ozone solubility should reach 0.3–0.5 mg/L, requiring 2 g of ozone per cubic meter of water. Higher concentrations, above 8 mg/L, are easily achieved in practice. Author: Xia Jin, Huikang Ozone Generator Factory Website: http:// Vegetarians Size 3 Empty Capsule Vegetarians Size 3 Empty Capsule,Natural Empty Vegetable Hard Capsules,Empty Veggie Capsules,Empty Vegan Pill Capsules Ningbo Jiangnan Capsule Co., Ltd. , https://www.jncapsule.com