Stipe-n Cap said:

BeefSupremeJr said:

Im not sure if stipe is ever going to post again....

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B Traven said:

"It works" always begs the question of what constitutes "working."

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B Traven said:

"It works" always begs the question of what constitutes "working."

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Published reports ascribe good germicidal activity to hydrogen peroxide and attest to its bactericidal, virucidal, sporicidal, and fungicidal properties.

Hydrogen peroxide is active against a wide range of microorganisms, including bacteria, yeasts, fungi, viruses, and spores. A 0.5% accelerated hydrogen peroxide demonstrated bactericidal and virucidal activity in 1 minute and mycobactericidal and fungicidal activity in 5 minutes.

Hydrogen peroxide works by producing destructive hydroxyl free radicals that can attack membrane lipids, DNA, and other essential cell components.

Concentrations of hydrogen peroxide from 6% to 25% show promise as chemical sterilants.The product marketed as a sterilant is a premixed, ready-to-use chemical that contains 7.5% hydrogen peroxide and 0.85% phosphoric acid (to maintain a low pH). The mycobactericidal activity of 7.5% hydrogen peroxide has been corroborated in a study showing the inactivation of multidrug-resistant M. tuberculosis after a 10-minute exposure.

Commercially available 3% hydrogen peroxide is a stable and effective disinfectant when used on inanimate surfaces. It has been used in concentrations from 3% to 6% for disinfecting soft contact lenses (e.g., 3% for 2–3 hrs) tonometer biprisms, ventilators, fabrics, and endoscopes.

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“Alcohol” refers to two water-soluble chemical compounds—ethyl alcohol and isopropyl alcohol—that have generally underrated germicidal characteristics.

These alcohols are rapidly bactericidal rather than bacteriostatic against vegetative forms of bacteria; they also are tuberculocidal, fungicidal, and virucidal but do not destroy bacterial spores. Their cidal activity drops sharply when diluted below 50% concentration, and the optimum bactericidal concentration is 60%–90% solutions in water (volume/volume)

The most feasible explanation for the antimicrobial action of alcohol is denaturation of proteins. This mechanism is supported by the observation that absolute ethyl alcohol, a dehydrating agent, is less bactericidal than mixtures of alcohol and water because proteins are denatured more quickly in the presence of water.

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The main chemical in bleach and chlorine is calcium hypochlorite. In bleach, about 5.25% of chlorine is present in each gallon, the remaining content is water and a small amount of salt that keeps the chlorine as a liquid. Chlorine contains calcium hypochlorite at a much higher rate.

Hypochlorites, the most widely used of the chlorine disinfectants, are available as liquid (e.g., sodium hypochlorite) or solid (e.g., calcium hypochlorite). The most prevalent chlorine products in the United States are aqueous solutions of 5.25%–6.15% sodium hypochlorite (see glossary), usually called household bleach.

The exact mechanism by which free chlorine destroys microorganisms has not been elucidated. Inactivation by chlorine can result from a number of factors: oxidation of sulfhydryl enzymes and amino acids; ring chlorination of amino acids; loss of intracellular contents; decreased uptake of nutrients; inhibition of protein synthesis; decreased oxygen uptake; oxidation of respiratory components; decreased adenosine triphosphate production; breaks in DNA; and depressed DNA synthesis. The actual microbicidal mechanism of chlorine might involve a combination of these factors or the effect of chlorine on critical sites.

Low concentrations of free available chlorine (e.g., HOCl, OCl–, and elemental chlorine-Cl2) have a biocidal effect on mycoplasma (25 ppm) and vegetative bacteria (<5 ppm) in seconds in the absence of an organic load.

Hypochlorites are widely used in healthcare facilities in a variety of settings.Inorganic chlorine solution is used for disinfecting tonometer heads and for spot-disinfection of countertops and floors.

Chlorine long has been used as the disinfectant in water treatment.

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The above lists the appropriate applications and concentrations for h2o2, alcohols, and bleach.

Source: Center for Disease Control

https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html#

Perhaps this is helpful?

Tldr= use alcohol for working surfaces; bleach for floors, rooms, tents.

Perhaps use h2o2 for disinfecting wild field specimens

Stipe-n Cap said:

Perhaps this is helpful?

Tldr= use alcohol for working surfaces; bleach for floors, rooms, tents.

Perhaps use h2o2 for disinfecting wild field specimens

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The pressurized steam makes contact with load surfaces, penetrating voids to condense and make contact with microorganisms. While purging is necessary to penetrate voids in the media and to achieve sterilization temps, clean/rinsed grains are required to take full advantage of these mechanisms. An overburden of filth not only increases bioburden but prevents contact with the grains surface where CFUs (colony forming units) reside.
If steam didn't penetrate the load, it wouldn't transfer latent heat to the surfuce upon which it condenses to denature the DNA of microorganisms. (Where voids are present)

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