*Brief Review of Decontamination Solutions*
By: Haumana
14 April 2005

This is a supplement to the excellent article done in 2002 by Californian: Field Decontamination

There are four major types of decontamination solotions that you will need to know about and learn to use: Chlorine Compounds; Alcohols; Phenolic Compounds; and Quaternary ammonium chlorides. Of these four, chlorine compounds and phenolic compounds will be the two that most survivalists will use. There is one very distinctictive difference in these two classes of compounds of which one MUST be aware...chlorine is more corrosive to metals than are the phenolic compounds.

Most of the remainder of theis article is taken verbatim from the 2002 CDC Biological Spill Response Guide and you are advised to reade ther entire guide for a more in depth view of this issue.

Four Most Commonly Recommended DISINFECTANTS for Use in CDC/ATSDR Infectious Disease Laboratories:

NOTE: Any mention of trade names is for identification purposes only and is not intended as an endorsement. Proprietary disinfectant products should be used in accordance with the manufacturer’s instructions for concentration, contact time, or other conditions of use.

1. CHLORINE COMPOUNDS. Powerful germicides with a wide spectrum of activity, lack of toxic residuals, and low cost. Like other halogens, they are highly reactive with organic matter and must be used either on a clean surface or in high concentrations. They are corrosive to metals, and rinsing is necessary when using concentrated solutions. Sodium hypochlorite solutions possess intermediate-level disinfectant properties, including some sporicidal activity against bacterial spores such as Bacillus anthracis. Commonly available sources of sodium hypochlorite solutions are proprietary products, household chlorine bleach, and reagent grade chemical. Sodium hypochlorite solutions are excellent laboratory disinfectants for incubators, tabletops, and laboratory spills. When using proprietary versions of sodium hypochlorite solutions, please read and follow label instructions for use carefully. Proprietary products may be more highly concentrated compared to household chlorine bleach, which in the U.S. is typically available at a concentration of 5.25% free available chlorine. NOTE: 5.25% chlorine is equivalent to 52,500 parts per million (ppm). If household chlorine bleach is used, two working solutions are generally recommended: 5000 - 6000 ppm for initial decontamination of organic spill material, and 500 - 600 ppm for disinfection of cleaned surfaces. The directions for preperation of these solutions are listed on the following page. These dilutions are adequate for decontaminating surfaces with blood or other potentially infectious material. For maximum potency, the working solutions should be prepared fresh at the time of use or daily as needed. Coxiella burnetii, the causative agent of Q fever, is not inactivated by 5% Clorox or Alcide (10:1:1) after 24 hours of contact time at room temperature.

To prepare a 5000 - 6000 ppm solution from a 5.25% bleach solution:

English: Add 1¼ c. (12.8 oz.) bleach to 1 gal. of water (128 oz.), or ¾ c. (6 oz.) bleach to 2 qts. of water (64 oz.), or (3 oz.) bleach to 1 qt. of water (32 oz.).

Metric: Add 500 mL bleach to 4500 mL of water, or 50 mL bleach to 450 mL of water, or 5 mL bleach to 45 mL of water.

To prepare a 500 - 600 ppm solution from a 5.25% bleach solution:

English: Add ¼ c. (2 oz.) bleach to 1 gal. (128 oz.) of water

Metric: Add 50 mL bleach to 4950 mL of water, or 5 mL bleach to 495 mL of water.

2. ALCOHOLS. In concentrations of 70 to 90%, alcohols are an excellent disinfectant of intermediate germicidal activity. Isopropyl alcohol is widely used as an antiseptic and for rapid decontamination of small objects. It does not inactivate picornaviruses, whereas ethyl alcohol does. Alcohols can form flammable mixtures with air and should be used with care for surface disinfection in closed areas, such as biological safety cabinets. For emergency disinfection of certain items, immersion in 75-90% ethyl alcohol for 15 minutes is recommended. Coxiella burnetii is inactivated by either 70% ethyl alcohol or 5% chloroform after a contact time of 30 minutes.

3. PHENOLIC COMPOUNDS. These compounds, derived from coal tar, were first used as wound dressings, but today have a wide use as general disinfectants. Examples are ‘Lysol’ (cresol and soap solution) and ‘Stericol’ (xylenol-rich cresylic acid and soap solution), both of which are active against viruses and bacteria but less active against bacterial spores. They are particularly effective for lipid-enveloped viruses. Working solutions of phenolics at pH 8 or below are most effective against microorganisms. However, treatment of Coxiella burnetii with a 5% solution of Lysol failed to inactivate after 24 hours at 250 C. One is cautioned that there are several products in the market with the Lysol moniker. Only the Lysol Concentrate - Original Scent; National Stock Number 6840005987327; Manufacturer Name RECKITT & COLMAN INC; with the active Ingredient Name ORTHO-BENZYL-P-CHLOROPHENOL is what you what to get.

4. QUATERNARY AMMONIUM COMPOUNDS. This category of compounds has been found to be highly effective against an extremely wide range of microorganisms, including gram positive and gram negative bacteria, fungi and some viruses. Quaternary ammonium chlorides are odorless and have low oral toxicity and skin irritation at concentration of 400-500 ppm of quaternary used for disinfection. The germicidal activity of quats increases as the pH increases. Commercially available Enviro-Chem (N-akyl dimethyl benzyl and ethylbenzal ammonium chlorides) at a 5% solution will inactivate Coxiella burnetii within 30 minutes at 250C.

The following is dated and a revision will be made ASAP:

Field Decontamination and Disposal:

Dermal Exposure: Immediately and thoroughly scrub skin with brush using soap and water; wash with 1/10th concentration of sodium hypochlorite (reduce commercial hypochlorite from 5.25% to 0.5% by mixing one part sodium hypochlorite to 9 cups of water); minimum surface contact time to 10 to 15 minutes.

Non-Cavity Injury Exposures: 1/10th concentration of hypochlorite may be instilled in non-cavity injury exposures and then removed by suction to an appropriate disposal container; sodium hypochlorite not recommended for open abdominal exposures (may form lesions) or brain and spinal cord injuries.

Other Decontamination: Apply 1/10th concentration of hypochlorite to cadavers, extreta, spills of body fluids; apply 1/100th concentration (1/4 cup hypochlorite to 1 gallon of water) to floors, clothing, equipment and other surfaces.

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