About Us » Chlorine dioxide gas - The gassing process

CD Process


Similar to all other decontamination methods, CD gas decontamination is a multi-step process. The 5 steps of the CD gas process are pre-condition, condition, injection, exposure, and aeration.

Accumulated PPM-HRS

The Exposure step is controlled through an "area under the curve" accrual of gas concentration until a target dosage has been met.

Pre-condition

Raising of relative humidity (RH) levels to between 60-75%.

Condition

Hold time once relative humidity set point has been reached.

Charge

Generation and delivery of chlorine dioxide gas.

Exposure

Hold time once gas concentration set point has been reached.

Aeration

Removal of chlorine dioxide gas from chamber.

Cycle Progression 0510301602100%20%40%60%80%00.30.50.81Elapsed Cycle Time(min)Humidity% RH(mg/L)CD Concentration
Time Line Chlorine Dioxide Gas
0 0
5 0.65
10 0.65 0
30 0.65 1
160 0.65 1
210 0 0
Pre-condition
Condition
Charge
Exposure
Aeration
Accumulated
PPM-HRS

Process Advantages:

Safer on materials than VPHP, bleach, ozone, and liquid chlorine dioxide solutions
  • Non-carcinogenic
  • Non-flammable at use concentrations.
  • Non-explosive at use concentrations, no need for Damage Limiting Construction (DLC). Chlorine dioxide can become explosive at concentrations of 10% in air, however normal use concentrations are 0.04%, approximately 250 times less.
  • Residue free process
Chlorine dioxide is a true gas at ambient temperature
  • Complete distribution as chlorine dioxide is governed by gas laws
  • No condensation, quick aeration
Accurate concentration monitoring
  • Due to its yellow-green color, chlorine dioxide can be accurately measured with a spectrophotometer
  • Other agents, such as VPHP, cannot be accurately monitored as concentration is not uniform throughout area due to condensation and distribution gradients
Size scalable
  • The chlorine dioxide gas decontamination process can be easily scaled up to volumes of millions of cubic feet.
Flexible process
  • Effective at low concentrations
  • Effective over wide temperature range
  • Effective under ambient or vacuum pressures
  • Effective against a wide range of organisms
Please call Biosafety on 1300 379 996 or info@biosafety.com.au to discuss your biological decontamination needs further. Biosafety services Australia and New Zealand.