|Principal characteristics||Oxidising gas - CAS no. 10028-15-6 / EG no. 233-069-2|
|Concentration||Up to 18 % by weight in oxygen/oxygen-enriched air|
|Solubility in water by weight (at 20°C)||0.003 g/l (3 ppm)|
|Vapour densitiy||1.6 (1 = air)|
|Flammability||Non-flammable/vigorously supports combustion|
|Appearance and odour||Ozone is colourless at all concentrations experianced in the industry. It has a pungent characteristics odour usually associated with electrical sparks. The odour is generally detectable by the human nose at concentrations of 0.02 and 0.05 ppm.|
|Fire/Explosion and hazard data||Ozone is a powerful oxidising agent. Oxidation with ozone evolves more heat and usually ignites at a lower temperature than oxidising with oxygen. Ozone reacts with non-saturated organic compounds to produce ozonides, which are unstable and may decompose with explosive voilence. Ozone is an unstable gas that, at normal temperatures, decomposes to biatomic oxygen. At elevated temperatures and in presence of certain catalysts such as hydrogen, iron, copper and chromium, this decomposition may be explosive.|
|Flash point||Not applicable|
|Auto ignition temperature||Not applicable|
|Conditions contributing to instability||Ozone spontanenously decomposes under all ordinary conditions, so that is not normally encountered except in the immidiate vicinity of its production. Decomposition is accelerated by contact with solid surfaces, by contact with chemical substances and by the effect of heat.|
|Incompatibilities||Ozone is a power oxidising agent and reacts with all oxidising materials, both organic and inorganic. Some reaction products are highly explosive.|
|Hazardous decomposition products||None|
Health Hazard Data
|Permissible Exposure Limits||The following limits are widly accepted (USA, Sweden, UK and other parts of Europe):|
- 8 hour per day/5 days per week (occupational exposure limit) - 0.1 ppm
- 15 minutes (short term exposure limit) - 0.3 ppm
|Toxicology of ozone||
The acute and chronic effects of excessive exposure to ozone have been well investigated. Exposure to concentrations of ozone in excess of several tenths of a ppm sometime cause reports of discomfort in a small susceptible portion of the population. This can be in the form of headaches of dryness of the throat and mucous membranes of the eyes and nose following exposures of short duration. Repeated exposure to ozone at such concentrations at 24-hour intervals, however, caused no further increase in airway irritability. In fact after the first exposures, additional exposures to ozone had progressively lesser effects suggesting that tolerance may develop over time.
Ozone has been shown to be more injurious at concentrations exceeding 2.0ppm over several hours, such as experienced by gas shielded arv welders. The primary site of acute effects is the lung which is characterized by pulmonary congestion. This acute impact subsided in welders when exposures where reduced to less than 0.2ppm. Based on animal studies, exposure over 10 to 20ppm or an hour or less believed to be lethal in humans although there has never been a single recorded fatality attributed to ozone exposure in more than 100 years of commercial use. (Compare with this experience with Chlorine as which has claimed many victims in peacetime as well as during war).
With respect to long term or chronic toxicity, ozone is a radiomimetic agent, i.e. the effects of long term exposure to excessive ozone exhibits the same affects as excessive exposure to sunlight. These effects are drying of the dermal surfaces and general ageing of exposed tissues. Ozone is not generally regarded or suspected of being a human carcinogen, neither does in exhibit tertogenic or mutagenic properties.
In the event of an ozone leak:
|Disposal of waste ozone gas||It is accepted practice, and required by statute in some jurisdictions, that Ozone gas should not be released into the atmosphere but should be destroyed using an approved ozone destruction method. (Catalytic, thermal, or absorption).|
|Disposal of waste ozone gas||
All potential outlets of ozone gas into the occupied areas or external atmosphere should be identified.
|Disposal of waste ozone gas||