Relation of Ozone Concentration with Safety and Effects
Ozone is a gaseous substance with a strong oxidizing power that gives us good effects. However, as ozone is harmful to living organisms on the other hand, we have to understand well the relation of ozone gas concentration with effect and harm so that we can make the most of its effects in compliance with safety requirements. To this end it is essential for us to make accurate management of the concentration of ozone. Shown in Table 1 is part of the relation between the concentration and beneficial effect or harm. A guideline as to the safety standard of ozone in a work environment is laid down by the Society for Occupational Health and Permissible Concentration Committee.
Table 1. Ozone Concentration and Its Characteristics
Concentration (ppm) | Characteristics (Effect and Harm) |
---|---|
0.02-0.05 | No ozone odor is felt below this range although there are great differences among individuals. As the permissible value is 0.1ppm at present, no odor ensures an absolute safety. So, the human sense of odor makes an excellent and most inexpensive monitor. |
0.05-0.1 | Permissible value for eight-hour labor (40 hours per week). Ozone odor is felt. |
0.3 | Permissible value when exposed for a short time of 15 minutes or less. |
0.5 | In case a healthy person does a contingent work for a short time (within one hour), there is no worry with less than this concentration. However, ozone irritates nose and throat. Too much irritation may cause headache, chest pain, respiratory thirst or coughing. You are suggested to wear a mask with activated carbon. |
0.5-1.0 | With more concentration than this level and long operation of one week or longer, ozone sterilizes inside of the room, deodorizes and gives a cockroach repelling effect²⁾. |
10 | In some dozens of minutes you may become unable to breathe, suffer pulmonary edema and go into a coma. |
40 | Sterilizing effect equivalent to formalin gas, used for disinfection of aseptic hospital wards³⁾ |
1) American Conference of Governmental Industrial Hygienist; Ozone, Documentation Review/revised, 453, 1987, CAS; 10028-15-6”
2) Published Unexamined Application № . 62-215509, Title : Cockroach Repelling Method applied by Shigeo Ohki
3) Toru Masaoka, “Aseptic patient room in Osaka Medical Center for Cancer and Cardiovascular Diseases” Lifestyle-related diseases, 20(1), 15-21, 1979
They adopted the values from those laid down by the American Conference of Governmental Industrial Hygienists. They regulated the permissible concentration of ozone at 0.05~0.1ppm for eight working hours per day, 40 hours per week, and at 0.3ppm for an exposure of 15 minutes or shorter. ¹⁾
You can measure an ozone concentration within the range related to safety management in use of an inexpensive densitometer of gas detection type which is available at 10,000 yen or a little more in the market.
臭氧安全浓度是多少?
根据清华大学编的《臭氧技术应用文集》一书,将有关臭氧应用浓度按安全浓度空气、应用浓度、水中应用浓度、环境浓度及感知浓度,分类摘录,以便在应用中查找。 安全浓度人们允许接触的臭氧浓度不大于0.2mg/m3。
臭氧工业卫生标准: 臭氧协会: 0.1 ppm,接触10小时 美 国: 0.1 ppm,接触 8小时 德、法、日 本: 0.1 ppm中 国: 0.15ppm
家用臭氧柜外臭氧泄漏量不得超过0.2mg/m3(指1.5米以外),一个周期后残留浓度不得大于0.2mg/m?。
动物试验表明,臭氧毒性的起点浓度为0.3ppm,而人对空气中臭氧可嗅知的浓度为0.02~0.04ppm,根据臭氧对肺功能毒性的试验结果,提出1.5~2.0ppm为臭氧允许浓度的上限。卫生部规定臭氧高允许浓度为0.2mg/m?。