Bleach

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Bleach

• Mechanism
• Enzyme inactivation enters cell and interacts
  with cytoplasmic enzymes
• Particularly sulfhydryl enzymes by HOCl

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Halogens

• Chlorine hypochlorites
• Iodines
• Tincture of iodine
• Iodophores
• Chlorine liberating cpds (1960s)

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Bleach

• Mechanism
• Enzyme inactivation enters cell and interacts
  with cytoplasmic enzymes
• Particularly sulfhydryl enzymes by HOCl

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Chlorine Bleach

• NaOCl H20 HOCl NaOH
• HOCl H OCl (hypochlorite ion)
• Hypochlorous acid
• Efficacy depends on pH of solution

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OH

-
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Quats

• Mechanism of Action
• Protoplasmic poisons or protein coagulants
• Denature proteins
• Alter permanence of cell wall allowing leakage
• Temperature coefficient
• Irritants

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Quats

• N atom saturated at four valences with four
  different organic residues
• Bound to covalently and anionically
• usually Cl or Br
• Linked to cationic portion by electrovalent
  bonding

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Benzalkonium Chloride

• Benzalkonium chloride was the earliest Quat
  also known as BAC
• Quenching
• Pseudomonas infections in patients

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Ethanol and Isopropanol

• Adding Isopropyl alcohol to ethanol increases
  bacteriocidal properties
• Methanol is not very bacteriocidal
• Mechanism
• Denatures bacterial proteins

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Alcohols

• Mechanism of action
• Dissolves lipids
• Denatures proteins
• Flammable
• Irritates and dries skin

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Iodophors

• I2 tincture or solution has been used as long as
  bleach
• Complexes with surfactant or carrier
• Cationic
• Anionic
• Non-ionic

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Betadine

• Polyvinyl pyrovidone iodine
• Povidone iodine
• 1 available I2 150ppm

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Wescodyne

• Iodine Detergent
• 1.6 available I2
• Recommendations for dilution
• 3 ounces to 5 gallons H2O 75ppm
• Mechanism
• Iodization of protein residue cpds.
• Complex with sulfhydryl group and amino acids

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Germicidal Properties

• Elemental iodine I2
• May hydrolyze to form
• I2 H2O HOI I
• I2 H2O H2OI I

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Aldehydes

• Formaldehyde (Formalin 37 HCHO)
• 37 (wt) formaldehyde and gas in H20
• 10 methanol added to inhibit spontaneous
  polymerization of monomeric formaldehyde

H H C O HOH HO-C-OH H
H
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Other aldehydes

• Paraformaldehyde linear polymer of monomeric
  HCHO
• When heated sublimes and liberates pure HCHO gas
• HCHO also present in organic residues melamine
  HCHO

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Aldehydes Glutaraldehyde

• Broad spectrum, pH dependent
• Pungent,irritant, toxic
• Cold sterilant 

World Health Organization
National Institutes of Health

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Gluteraldehyde
CH2-CH(OH)2
CH2
CHOH
CH2-CHO
H2O (OH)
CH2
CH2
CH2
O
CH2-CHO
CH2-CH(OH)2
CH2
CHOH

• Has tendency to polymerize
• pH increases
• Short shelf life 28 days
• Optimal pH 7.5 8.5

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Bleach

• Mechanism
• Enzyme inactivation enters cell and interacts
  with cytoplasmic enzymes
• Particularly sulfhydryl enzymes by HOCl