• Creates hypertonic environemt and plasmolyzes pathogen, dessicates food, interferes with enzyme activity, and wakens DNA's molecular structure
• Salt: no good against halophiles
• Sugar: No good against saccharophiles

Used as disinfectants or antispetics; can sterilize with prolonged application

useful elements: chlorine, iodine

too reactive: fluorine, bromine

• liquid or gaseous forms
• broad applications
• good against most microbes
• disrupt disulfide briges and oxidize cysteine group

Hypochlorites (OCl) are most commonly used form of chlorine. Bleach is sodium hypochlorite.

Must dilute it, and only good for 24 hours

• For tissues and medical equipment
• Good against most microbes
• disrupt hydrogen-and sulphur-binding

• Free iodine (I₂), tinctures 
• Iodophors (I+ polymore)

• Germicidal
• Contain -OH group
• Ethyl and isopropyl alcohol used medically
• at high concentractions its a dessicant
• At moderate concentrations it is a protein denaturant
• used for skin, work surfaces, and medical equipment
• logistically the best option, convienent, low cost, tolerable 

• Benefits: considered more microbicidal (used in surgery and spinal epidurals) used for blood cultures, people allergic to alcohol and blood-alcohol testing
• Drawbacks: stains skin and degrades rubber stoppers (blood collection tubes)

• disrupts cell membranes and denatures proteins. 
• equal in efficacy to iodine options
• used for people allergic to iodine, hand scrubbing, and catheter insertions

• microbicidal but rarely sporicidal
• all have one or more aromatic ring with OH and possibly other functional groups
• Low concentrations disrupt enzymes
• High concentrations disrupt enzymes, membranes, and walls
• Ex) Lysol and Triclosan 
• pHisoHex was discontinued 

• Hydrogen peroxide (H₂O_{2): free radicals, microbes have catalase to neutralize the free radicals, but not in quantities humans apply.} 
• _{General disinfectant (short exposure)}
• _{Sterilant for surgial or delicate equipment (long exposure)}
• _{Relatives: peracetic acid and ozone}

• Disinfectants or sanitants
• Polar molecules that reduce surface tension (act as surfactants) can disrupt membranes, have both hydrophillic and hydrophobic components.
• Anionic detergents (dishsoap, handsoap) have low antimicrobial activity and are more milder detergents
• Cationic detergents (quaternary ammonium compounds) have more antimicrobial activity and are used more for surfaces. 
• limited uses

• Leads to antibiotic/antibacterials resistance
• hypersterile enivornments may not stiumlate young immune system properly
• clears skin of beneficial bacteria 

• Very strong antimicrobial
• Germicidal
• Mercury and silver show most promise
• used in salt form, usually in solution
• strong properties at small concentrations disrupt proteins
• highly toxic with many drawbacks
• Thimerosal is used as preservative in flue vaccine

• Disinfection and sometimes sterilization
• Disrupts proteins on surface of and inside the cell through alkylation of amino acids
• Can be used in vaporized form via chemiclaves

• gaseous (when dissolved in water its formalin)
• strong disinfectant OR preservative
• used for surgical instruments (they need to be rinsed after treatment)

• Sterilant
• used for diagnostic and therapeutic equipment; dental tools, vaccine preservative

• Sterilants
• Three most commonly used are Ethylene oxide (ETO), propylene dioxide, and chlorine dioxide
• all work through alkylation, disrupt DNA and proteins
• used in chemiclaves

• microbicidal and sporicidal
• its explosive, slow working, toxic to humans, carcinogenic, and deconned items need to be "areated/ de-gassed" before use