Occupational exposure limits
The following occupational exposure limits for ozone apply in the UK, other parts of Europe, the USA and Canada:
the limit for regular exposure for up to 8 hours per day, 5 days per week (Netherlands: 0,06 ppm)
exposure should be limited to 15 minutes at a time
| ||O3 |
up to 18% by weight in oxygen
2,14 kg O3/m3 @ 0°C 1013mbar
3 ppm at 20 °C
non-flammable, but vigorously supports combustion
Ozone is a colourless gas at all concentrations experienced in industry. It has a pungent characteristic odour usually associated with electrical sparks and thunder storms. The odour is generally detectable by the human nose at concentrations between 0,02 and 0,05 ppm or approx. 1/100th of the recommended 15 minute exposure level.
Ozone is an unstable gas which decomposes to biatomic oxygen at normal temperatures. Decomposition is accelerated by contact with solid surfaces, by contact with chemical substances and by the effect of heat. Ozone is produced by ozone generators which aren normally fed by oxygen generators. Ozone injection is done by diffusors or venturi's.
Because ozone is an unstable gas, there may be danger of explosion at high temperatures in the presence of materials such as hydrogen, iron, copper and chromium. In practice, occasional fires have occurred inside ozone generators, but with the exception of experiments under extreme conditions, we know of no reports of explosions.
For information on ozone monitors and sensors for room control.