Disinfectant Fogging Techniques

Wet or Dry

• There are two types of fogging solutions available: wet or cold and dry or thermal. The wet solution is a mist with particles that is applied in a fine spray. The dry type of fogger delivers the disinfectant as a gas with minimal moisture and can even be applied as a powder. Both types of fogger are effective as disinfecting agents for large areas where hand disinfection is not possible or practical. Both types of fogger materials are measured in microns to describe the miniscule size of the droplets or particles.

Safety

• Fogger disinfecting systems produce fine particles that float in the air and can be inhaled. These are chemicals whose direct effect on the lungs are varied and potentially hazardous. The Occupational Safety and Health Administration (OSHA) recommends that respirators be used when fogging an area. The use of gloves and eye protection is also recommended to avoid exposure to the fine particles delivered with fogging technology. You should also wear long pants and a long-sleeved shirt while applying the chemicals. The fogging solutions may be liquid or pellet and should be mixed with caution in a well-ventilated area.

Wet Foggers

• Wet foggers are used to disseminate water-based chemical formulas and include tri-jet, ultra-low volume and air blast atomizers. The tri-jet fogger delivers large particles that can leave surfaces wet and are not common in modern equipment. The ultra-low volume sprayers produce finer particles, 8 to 15 microns in size. Air blast atomizers produce a more typical "fog," where the particle size is as small as 50 to 200 microns. This is the preferred method where moisture-sensitive items are contained.

Dry Foggers

• Dry fogging uses heat as a source for turning moisture into a vapor. These are also called hot or thermal foggers. The chemicals used are solvent- or petroleum-based. When heat is applied, they turn into a smoke-like fog. The tiny size of dry fog droplets minimizes surface residue and increases safety. Dry foggers may be remote control machines or manually operated. Dry foggers provide broader disinfection than wet foggers, which leave particle residues and may pose a greater health risk through direct contact.