Safety of Ozone

When it comes to environmental disinfection and odor removal, nothing can complete the task more thoroughly, quickly and efficiently than using an ozone generator. Whether there are pollution or odor problems in hotels, apartments, rental homes or food processing plants, ozone generators can be used in a variety of applications to bring the environment back to what it was.

Although ozone generator has long been successful in sterilization and odor removal, since it is a strong oxidant, the improper use of ozone can potentially cause potential health risks.

Since safety is our topic, in the following, we will discuss symptoms caused by the ozone inhalation, the control of the running time and the different standards on the ozone concentration, precautions for ozone applications, and how to deal with ozone-related situations.

Ozone generators are undoubtedly an excellent solution for removing odors and killing harmful microorganisms. However, a high concentration and long exposure time can also be dangerous. Prolonged exposure to ozone gas can cause the following symptoms:

• Chest pain
• Stimulation to the throat, nose, or eyes
• Shortness of breath
• Pneumonia
• Respiratory tract infection
• Cough

When using an ozone generator, the running time of the device is determined by the type and severity of the problem that needs to be addressed. For example, gas, smoke and fume can be easily removed in a very short period of time. But it takes a long time to remove bacteria, molds, germs, pungent smell, heavy cigar smoke, etc.

The potential impact of ozone on certain sensitive items should also be considered when using an ozone generator. For example, for odor removal in cars with a lot of leather materials, its running time should be limited to 30 minutes. If the odor problem persists, such short-term treatment can be applied repeatedly for several time until it is resolved.

Since ozone will to some extent accelerate the aging of rubber materials, the use of an ozone generator in a garage should be restricted within 30 minutes.

Respectively, OSHA and NIOSH are divisions of the U.S. Department of Labor and the Centers for Disease Control and Prevention. Even though they set safety and health standards that are not enforced under U.S. law, they do provide valuable advice on ozone applications. They provided restrictive guidelines for human exposure time to ozone and concentration of ozone based on time-weighted averages in the following:

• Light work: No more than 0.1ppm over an 8 hours period
• Short-term: No more than 0.3ppm over a 15 minutes period
• Immediately Dangerous to Life and Health: 5.0 PPM

The EPA’s safe standard for ozone use is 0.07 PPM over an 8-hour period. For ozone use in bottled water, the dissolved level of residual ozone should be limited to 0.4 PPM, which is sufficient to kill E. coli 0157:H7 in drinking water.

Ozone has been given GRAS approval by the USDA and the FDA for direct contact with foods, including all meat and poultry products. Ozone is also certified by the National Organic Program in the USDA as an acceptable additive in organic food growing and production.

The FDA, an agency within the Department of Health and Human Services, also regulates medical devices. As part of the regulation, the FDA has limited ozone production in indoor medical devices to no more than 0.05 PPM at any given time.

The safety standard for ozone concentration from World Health Organization is no more than 0.05 ppm for 8 hours, which is even higher than those from the OSHA and the NIOSH.

The threshold that we can tell the existence of ozone in the air is 0.005-0.02 ppm, which is 1/10 of the density in the standard set by the World Health Organization. However, in addition to relying on the feeling, it is best to have an ozone gas detector when using an ozone generator in an indoor environment. The device shall have the following alarm functions:

• The 1^st warning will be given when an ozone level of 0.1 PPM is detected. If necessary, the ozone generator can still keep running.
• The 2^nd warning will be given when an ozone level of 0.3 PPM is detected. The ozone generator should be shut down when this warning is given.

In addition, when handling a high concentration of ozone, there should be an ozone destruction device. It is capable of quickly and safely degrading excess ozone in the air which potentially poses a threat to human health.

When using an ozone generator for disinfection or odor removal purpose, refer to the following precautions to ensure both safety and a better treatment effect:

1. User’s Manual – To ensure the safe operation of an ozone generator, the user should carefully read the User’s Manual before use.

2. Properly Seal the Space – Make sure the environment is completely sealed. There should be no possibility of any leakage of ozone to be generated. Tapes can be used when necessary. Also, make sure that all plants and pets have been removed from the space.

3. Remove Sensitive Items – Rubber, plastics, fabrics, paint, metals and textiles are part of the sensitive items to ozone gas. Make sure the room is free of these items or properly sealed before an ozone treatment.

4. Treatment Time – The treatment time of an environment with an ozone generator should be determined by referring to the product manual and taking into consideration the size, the efficacy of the treatment and how polluted the space is.

5. Timer – Selecting an ozone generator with a timer can make the operation more convenient. With its help, a device can be turned off automatically at a specified time. If a manual shutdown is a must, to prevent the excessive ozone from entering the respiratory system, ensure that mouth and nose have been covered with a towel.

6. Ozone Diffusion Time – The direct exposure to ozone can cause harm to health. To ensure that the ozone left in the room has been fully dispersed, wait at least 30 minutes after an ozone treatment has been finished in a room.

7. Daily Maintenance – An ozone generator should be cleaned and maintained periodically, with related consumables exchanged when necessary according to the User’s Manual.

1. Inhalation of Ozone: The entering of ozone into the respiratory tract can cause a dry mouth, coughing and irritation to the nose, throat and chest, leading to breathing difficulties, headaches and fatigue. It may also aggravate bronchitis, emphysema and asthma. What needs to be done is to have him transferred to a well-ventilated area and loosen the tight clothing if there is. Then, seek medical advice in case of difficulty breathing.

2. Skin Contact: Ozone gases cannot be not absorbed through the skin. If there are still safety concerns, it is recommended to wash the skin with soap and water.

3. Eye Contact: Ozone can irritate the eyes and cause mild inflammation. In case of an ozone irritation to the eyes, flush the eyes with plenty of water for at least 15 minutes, keeping the eyelids apart to ensure that the entire surface of the eye can be flushed with water.