Media-Specific Disinfection

Surfaces and Air

Legal Issues1) It is a violation of Federal law to use an EPA registered product in

a manner inconsistent with its labeling.– Solution strength must be according to label

– Applications must be on the label

2) It is a violation of Federal law for a manufacturer to make real or implied claims for efficacy against organisms which are not on the label.– Creates problems when we encounter:

• FMDV

• Anthrax

• Norwalk

• SARS

• Avian Influenza H5N1

• Surface Disinfection = Inactivation in Place• Surface Cleaning = Removal of Contaminants

• Commercial products frequently combine disinfection and cleaning.

• Some disinfectants have cleaning properties• Recommendation (at least in clinical settings) clean

with disinfectant to avoid spreading contamination

Pre-Disinfect Clean Disinfect

Surface Disinfection

Surfaces

• What surfaces might you need to disinfect?– Household Surfaces– Food and Food Prep Surfaces– Clinical Surfaces– Laboratory– Industrial– Farm– Other???

Concerns for Disinfection of Surfaces

• Disinfectant Type/Concentration/Formulation• Contact Time• Type of Organisms/Level of Disinfection• Corrosivity and Other Surface Damage• Toxicity/Residual Toxicity• Other Residues• Odor• Type of Application and Rate

Concerns for Disinfection of Surfaces

• pH• Demand and Interfering Substances• Temperature • Water hardness• Soil load• Biofilm presence • Surface microtopography• Precleaning • Relative humidity • Compatibility • Storage of Product/Product age

Clinical/Dental Surface Disinfectants

Farm Surfaces

• Virkon S (potassium peroxymonosulfate)

• Nolvasan S (chlorhexidine diacetate)

• Bleach (sodium hypochlorite)

• Spectrasol (quat)

• Alcohols (ethanol and Isopropanol, 70-95%)

• Roccal D (quats with bis-n-tributylin oxide)

Surface Disinfection

• In study by CRA Foundation– 54 clinical surface disinfectants tested against TB and

Polio with and without presence of Blood

– 7 passed:• Household Chlorox (50:50)• Industrial Chlorox (50:50) • Biosurf• Lysol I.C.• Lysol II Spray• Indi-wipes with Lysol

Ozone Surface Disinfection•   Up to 14 PPM Ozone

@ 10GPM •   Onboard Ozone

Analyzer With Alarms •   Exclusive Off-Gassing

System •   Spray, Mist and Fog

Applicators;   Spray Arches Available

• Advertises a 3 Log Kill on First Application

UV Surface Disinfection• Conveyor Belts• Food Prep Surfaces• Laboratory and

Clinical Surfaces• Sterilization of

Packaging• Mail Systems

Cleaning and Disinfection of Floors

% Reduction

Soap and water 80.4%

Phenol 99.0%

Microbial Contamination of Mop Water

Soap(CFU/ml)

Phenol(CFU/ml)

Before cleaning 10 20

After cleaning one-third of ward

650 10

After cleaning two-thirds of ward

15,000 30

After cleaningcomplete ward

34,000 20

Disinfection of Food Surfaces

Chemical disinfection of Indoor Air

• Spraying– relatively large particles,

which have a higher wetting capacity, but stay in the air for less time

• Misting– smaller particles that have

increased penetration and uniformity

• Fumigation– combination of 2 or more

chemicals producing a vaporised form of the disinfectant

• Thermal Fogging– similar to misting but

involving heating of the disinfectant to produce a fine vapour

Chemical Disinfectants of Air

• Chlorine Dioxide• Ozone• VHP• Formaldehyde • Gluteraldehydes• Quat mixtures• Virkon (peroxy compound)• Sporocidin (phenolic)

Air Disinfection

• Chemical Disinfection– Spray, mist, fog, fumigation

• UVGI

• Ionization/Electrostatic Precipitation– Only one that removes

• Photocatalytic oxidation

UV Air Disinfection

• Forced Air or HVAC Duct Systems

• Full Air Systems

• Upper Air Systems

• Re-circulating Systems

• Microbial Growth Control– On Filter Surfaces

UV Air Disinfection: Duct Systems

• Integrated in to HVAC System

UV Air Disinfection: Upper Air

• Originally designed for TB sanitariums

UV Air Disinfection: MGS