Oct 15, 2014

Ebloa question? A Comparison of Commonly Used Surface Disinfectants - CDC, OSHA & EPA

OSHA/EPA - Bloodborne Pathogen Standard
In December 1991, OSHA promulgated a standard entitled "Occupational Exposure to Bloodborne Pathogens" to eliminate or minimize occupational exposure to bloodborne pathogens 214. One component of this requirement is that all equipment and environmental and working surfaces be cleaned and decontaminated with an appropriate disinfectant after contact with blood or other potentially infectious materials. Even though the OSHA standard does not specify the type of disinfectant or procedure, the OSHA original compliance document 269 suggested that a germicide must be tuberculocidal to kill the HBV.   To follow the OSHA compliance document a tuberculocidal disinfectant (e.g., phenolic, and chlorine) would be needed to clean a blood spill.  However, in February 1997, OSHA amended its policy and stated that EPA-registered disinfectants labeled as effective against HIV and HBV would be considered as appropriate disinfectants ". . . provided such surfaces have not become contaminated with agent(s) or volumes of or concentrations of agent(s) for which higher level disinfection is recommended." When bloodborne pathogens other than HBV or HIV are of concern, OSHA continues to require use of EPA-registered tuberculocidal disinfectants or hypochlorite solution (diluted 1:10 or 1:100 with water) 215, 228.  Studies demonstrate that, in the presence of large blood spills, a 1:10 final dilution of EPA-registered hypochlorite solution initially should be used to inactivate bloodborne viruses 63, 235 to minimize risk for infection to health-care personnel from percutaneous injury during cleanup.

Alcohol-, Phenol-, Chlorine-, and Quaternary Amine-Based Disinfectants

By Lauren Crawford, BS; Zhi-Jian Yu, PhD; Erin Keegan, BS; and Tina Yu, MS

Using proper surface disinfection can prevent infections that develop during hospitalization that are neither present nor incubating at the time of a patient's admission. There are important factors to consider when selecting a surface disinfectant. This paper discusses a comparison of the product types on the basis of the health-related issues of infection prevention, compatibility with equipment and gloves, as well as the safety of the disinfectant to hospital personnel.

Some ideal characteristics of disinfectants used on environmental surfaces include rapid action in a broad antimicrobial spectrum, maintained efficacy in the presence of protein or blood, low toxicity, user safety, and material compatibility. Some disinfectants have limited use because they do not meet all of these criteria. Table 1 shows a list of 10 disinfectants, the active ingredients, manufacturer, characteristics of the disinfectant, and a recommendation of the types of gloves that can be used with the product for up to one hour.
Spectrum and Rapidity of Antimicrobial Activity

The spectrum refers to the range of recommended product usage and the sphere of microbial kill tested, as well as the contact time and temperature, according to the manufacturer and the EPA-approved label. The 10 products that are mentioned in Table 1 are similar in antimicrobial activity because they all claim to be bactericidal, fungicidal, and virucidal. However, not all disinfectants claim to be tuberculocidal. Envirosafe, Coverage HB, Coverage Spray, and Ascend are all low-level disinfectants and they do not kill the tubercule bacillus (i.e., M. Bovis). Based on the disinfectant class, the range of antimicrobial activity is discussed in further detail below.

High concentration alcohol-based

Lysol I.C. Disinfectant Spray has a broad spectrum of antimicrobial activity with 79% ethyl alcohol and has a recommended surface contact time of 10 minutes. High concentration alcohol products are generally not advocated for instrument immersion since the high alcohol content volatilizes easily, and thus diminishes antimicrobial activity. Additionally, alcohols cannot be used as cleaners, which then requires the user to purchase a separate cleaner.

Dispatch can be used as a cleaner due to the presence of added surfactants and a deodorizer. It has a broad range of efficacy with a label claim contact time of two minutes at 20°. Both Babb and Alvarado et al. do not recommend chlorine-based compounds, such as the sodium hypochlorite contained in Dispatch, for disinfection of instruments and equipment. Robison et al. reported that a commercial disinfectant containing 0.55% sodium hypochlorite with a 2-minute contact time at room temperature displayed poor tuberculocidal activity. According to Robison's study, the average time required for a 6-log10 reduction was in excess of three hours. However, the CDC recommends that 5.25% sodium hypochlorite (household bleach) diluted to a concentration of 0.05% can be used for the decontamination of a blood spill.

Wex-cide, ProSpray, and Birex are germicidal, fungicidal, virucidal, and tuberculocidal in 10 minutes at 20°. Birex is a cleaner and deodorizer. Birex is not sold at the use-dilution, and therefore, diluting Birex involves an extra step. Surface disinfectants that require dilution can result in preparation errors, and incomplete disinfection due to an inappropriate disinfectant concentration.

Quaternary amine-based
Envirosafe, Coverage HB, Coverage Spray, and Ascend are all low-level quaternary amine-based disinfectants, and have a more prominently restricted efficacy range than the other products discussed herein. These product spectrums do not include tuberculocidal activity. With the exception of Coverage HB concentrate, they do not kill HBV (Hepatitis B Virus). Additionally, Envirosafe, Coverage HB, and Ascend are not sold at the optimum concentration and dilution is required. Envirosafe, Coverage HB, Coverage Spray, and Ascend can be used for ultrasonic cleaning and as general cleaners. The four quaternary amine products can also be used for (limited) instrument immersion for the allotted time to kill microorganisms. However, surface disinfectants in general are not recommended as permanent holding solutions.

Quaternary amine / low concentration alcohol-based

The synergistic mechanism of quaternary amines in the presence of alcohols involves the breakdown of the lipoprotein complexes by the quaternary amines in the cell membrane of microorganisms. The opening of the membrane thereby allows the alcohol, which is a protein denaturant, to penetrate the cell membrane and cause irreversible damage inside the cell. Cavicide has a broad spectrum of antimicrobial activity with a recommended surface contact time of 10 minutes at 20°. It can be used as a cleaner, as an ultrasonic cleaning solution, and for instrument immersion.
Resistance to Organics (Soils)

Including blood in all active ingredient efficacy testing is important because clinicians rarely deal with pure cultures of microorganisms. Clinically, microorganisms are usually contained within proteinaceous material such as blood, plaque, saliva, etc. Inclusion of these proteins in tests is important since these proteins interfere with the antimicrobial activity of disinfectants. For this reason, it is a good clinical practice--and a mandated labeling requirement from the EPA--to clean surfaces of gross debris prior to disinfection.

Read full By Lauren Crawford, BS; Zhi-Jian Yu, PhD; Erin Keegan, BS; and Tina Yu, MS at:  http://www.infectioncontroltoday.com/articles/2000/11/a-comparison-of-commonly-used-surface-disinfectan.aspx