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25 Cards in this Set
- Front
- Back
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Swab Testing
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-Rodac plates
-Petri Film -ATP |
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Water Quality
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-Hardness
-Bacterial Quality -Impurities -Temperature |
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Soap
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alkaline salts of carboxylic acids
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Synthetic Cleaner
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complex soils
-surfactants: lowers H20 tension -Detergent: penetrates/suspends soil |
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Cleaning compounds
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-Chelating Agents (sequestrants)
-Suspending agent (starch, CMC) -Saponifying Agent (NaOH) -Emulsifying agent (Na metasilicate) |
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Classification of Cleaning Chemicals
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Strong alkaline (caustic, NaOH)
Moderately alkaline (high pressure sprays) Mildly alkaline (manual cleaning) Strong Acids (HCl) Mild Acids (citric) Sodium hypochlorite |
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Factors Affecting Cleaner Effectiveness
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Type of soil
Amt. of soil Temp/conc of cleaner Contact time |
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heavy fat and oil deposits
burned/dried deposits Food waste deposits Protein waste deposits Mineral hard water deposits heavy mineral deposits |
Strongly alkaline
Strong alkaline Moderately alkaline chlorinated mildly acid cleaners strong acid |
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Sanitizing
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treatment of a cleaned surface with a chemical or physical agent to destroy disease/spoilage causing organisms.
are used at relatively low concentrations to reduce total vegatative cell pop. to a safe level |
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Criteria for a chemical sanitizer
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-produces fast microbial kill (5-log reduction)
-non toxic -deliverable -cost effective -safe to handle |
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Halogen sanitizers
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Chlorine
Iodine Quat |
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Chlorine
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Advantages
-Broad spectrum bacterocide -available in different states -most economical Disadvantages: - very corrosive - deteriorates easily - |
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Chlorine dosage
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amt of chlorine added to h20 (ppm)
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Chlorine demand
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amt of chlorine reacting w h2o impurities
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Residual chlorine
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remaining chlroine after the demand of h2o and any impurities has been satisfied
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Iodophors
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Advantages
-broad spectrum -less irritating -low toxicity -stable Disadvantages: - staining porous and plastic materials -poor activity against bacteriophages |
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Quat
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advantages
-good foaming and penetrating power -forms bacteriostatic film on surface disadvantages -long bacteriostatic residual -limited activity against gram negs |
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peroxy compounds
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advantages
-low foaming -no residue -broad spectrum Disadvantages -corrosive -losses effectivess if water is >0.2ppm |
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Acid Anionics
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advantages
-stable -non corrosive disadvantages -high cost -irritant |
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Carboxylic Acid
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Advantages
-low foaming -broad spectrum -low cost disadvantages -limited activity against fungi -corrosive |
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ClO2
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Properties
-soluble in cold water -must be generated on site Advantages -strong oxidizer -less corrosive disadvantages -saftey toxcity |
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O3 (ozone)
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Properities
-kills by lysis phenomenon Advantages -broad spectrum disadvantages -unstable -safety issues -cost |
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UV
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Properties
-mechanical disinfectant -energy destroys cells DNA molecules advantages: -activity independent of ph and temp -no residual taste or color Disadvantages -poor penetration -safety issues -bacterial regrowth |
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Comparative costs for water treatment
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UV -least
ClO2 - medium O3 - most (most useful) |
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Principles of Sanitary Facility Design
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1. Importance of Plant Site and Physical Environment
2. Establish Distinct Hygienic Zones 3.Control Flow of Material and Personnel 4. Control Accumulation of Water 5. Control Room Temperature Humidity 6. Control Room Air Flow, Quality 7. Site Elements Facilitate Sanitary Conditions 8. Building Envelope Facilitates Sanitary Conditions 9. Interior Spatial Design 10. Building Components and Construction Facilitate Sanitary Conditions 11. Utility Systems Prevent Contamination 12. Sanitation Integrated into Facility 13. Lighting Designed to Prevent Hazards 14. Stairs and Platform Walkways Constructed to Prevent Contamination |
