The Need for Disinfectants
Industry standards require transesophageal and endoscopy probes to undergo rigorous cleaning and high-level disinfection steps. At the conclusion of high-level disinfection, probes then must be stored in a dry and well-ventilated cabinet. In 2013, a total of 44 patients were infected with New Delhi metallo-beta-lactamase following endoscopic procedures due to inadequate disinfection.1 Endoscopy and transesophageal procedures can introduce microorganisms and chemical substances to unsuspecting patients if not properly disinfected and stored.
To mitigate the risk of potential outbreaks and exposures, rigorous procedures for cleaning and handling have been installed for probe storage and use. Any given procedure typically requires the use of one of several chemical agents to ensure high level disinfection.
With the sheer quantity of procedures carried out each year, how safe are the FDA recommended high level disinfectants (HLDs) used in probe reprocessing? To better understand, we need to take a closer look at these HLDs, including glutaraldehyde, orthophthalaldehyde, peracetic acid, and hydrogen peroxide.
Hydrogen Peroxide
HO-OH
Classification: Oxidizing Agent
Hazards: Oxidizer, Corrosive, and Irritant
General Exposure Symptoms: Corrosive to skin and mucous membranes, pulmonary inflammation, necrosis, swelling and hemorage if ingested
ACGIH Threshold Limit Value: 1.0 ppm
Stabilized hydrogen peroxide is an effective HLD for a variety of microorganisms including bacteria, yeast, fungi, viruses, and spores. Hydroxyl radicals in solution attack membrane lipids, cell components, and DNA.2 Some organic microorganisms can metabolically reduce hydrogen peroxide, making concentration important to ensure high level disinfection.
Stabilized hydrogen peroxide is an effective HLD for a variety of microorganisms including bacteria, yeast, fungi, viruses, and spores. Hydroxyl radicals in solution attack membrane lipids, cell components, and DNA.2 Some organic microorganisms can metabolically reduce hydrogen peroxide, making concentration important to ensure high level disinfection.
Peracetic Acid
C2H4O3
Classification: Organic Acid
Hazards: Acute Toxicity, Corrosive, and Flammable
General Exposure Symptoms: Corrosive to skin and mucous membranes, pulmonary inflammation, necrosis, swelling and hemorage if ingested
ACGIH Threshold Limit Value: 0.4 ppm
Peracetic acid is a common disinfectant used throughout the medical industry which can prevent biofilm formation. There is limited information on the mechanism of action regarding peracetic acid, but it is widely believed it operates similarly to other oxidizing agents, denaturing proteins and disrupting cell wall permeability.3
Peracetic acid, while an effective disinfectant, is toxic at nearly any measurable concentration. Peracetic acid inhalation results in pulmonary inflammation in addition to damaging of the mucous membrane within the respiratory tract.
Orthophthalaldehyde (OPA)
C8H6O2
Classification: Aldehyde
Hazards: Acute Toxicity, Corrosive, and Environmentally Hazardous
General Exposure Symptoms: Burns via any exposure route, perforation of stomach and esophagus, contact dermatitis, and respiratory irratation
ACGIH Threshold Limit Value: NA
OPA has been proven to be an effective alternative HLD to glutaraldehyde. It operates binding membrane receptors inhibiting functions and causing microorganism death.2 Unlike glutaraldehyde, it has a larger pH operating range and minimal odor.
OPA does have limited sporicidal capacity relative to glutaraldehyde. This decrease in disinfection efficiency makes OPA less attractive for probe disinfection. Additionally, OPA can damage skin and mucus membranes posing a serious risk when users are exposed to fumes.
Glutaraldehyde
C5H8O2
Classification: Aldehyde
Hazards: Health Hazard, Corrosive, Irritant, and Environmentally Hazardous
General Exposure Symptoms: Occupational asthma, contact dermatitis, shortness of breath, respiratory irritation, and central nervous system impairment
ACGIH Threshold Limit Value: 0.05ppm
Widely used since the 1960s, glutaraldehyde is one of the first HLDs used to reprocess medical instruments.4 The aldehyde functional group attacks groups of microorganisms such as hydroxyl, amino, carboxyl, and sulfhydryl.2 The attack is pH dependent and, while glutaraldehyde can be reused for several high level disinfection cycles, it must be monitored to ensure pH is effective for sporicidal activity.
Glutaraldehyde is a highly successful HLD and noncorrosive to most probe materials. However, the extremely low threshold limit value and known carcinogenic and mutagenic properties have led to it being banned in some countries.
AirClean Systems Solution
Regardless of the HLD you are using, the potential for harmful exposure is a real threat to safety. The characteristics that make HLDs effective across a wide array of microorganisms also make them a potential respiratory hazard.
The mitigation of these hazards can be controlled using proper personal protective equipment and through rigorous protocol to ensure safety during probe cleaning, sanitation, and storage. AirClean® Systems offers a product solution to each of these steps in probe handling. From soaking stations to storage, we offer the best protection in the industry.
Proper Filtration is Key to Your Safety
The HLDs used to reprocess semi-critical reusable medical devices all show low threshold limit values and potential hazards that healthcare professionals should be concerned with during scope and probe reprocessing. Irrespective of if the HLDs are in a soaking station or an automated reprocessor, they pose a significant safety concern. Exposure is a serious risk and through 25 years of HLD containment, AirClean® Systems’ bonded carbon filters have been proven to be effective.
AirClean® Systems’ bonded carbon filters have a predictable and consistent amount of carbon due to the bonding process. When it comes to HLDs, a major issue is the amount of carbon and the retention time during which the chemical is held inside the filter. Time and mass play a direct role in the ability of the filter to be effective and ensure the user a long filter life. Key factors in the containment of any chemical are retention time, molecular weight, and the overall mass of carbon available to capture the chemical.
Over the years, many companies have gone to sprayed-on carbon pelleted media type filters, which are cheaper, but not as effective. The pelleted spray-on carbon filters have minimal carbon surface area, little to no retention time, and limited carbon mass. These types of filters should not be used when containment of HLDs is critical.
To safeguard our customers, we use isotherm data to ensure our carbon filters have the capacity and longevity to keep you protected at all times. Using this data, we can determine our carbon’s adsorption capacity (percent by weight). Our bonded carbon filters are the largest in the industry, maximizing the amount of carbon per filter to keep your HLD fumes contained.
References
Association for Advancement of Medical Instrumentation. ANSI/AAMI ST91: 2015.
Center for Disease Control. Guidline for Disinfection and Sterilization in Healthcare Facilities. 2008.
Center for Disease Control. Peracetic Acid Sterilization. 2008.
OSHA. Best Practices for the Safe Use of Glutaraldehyde in Health Care. 2006.