Case Study: Successful Decontamination of an Aseptic Fill Isolator Using Chlorine Dioxide Gas

Isolators are gas-tight enclosures typically used in either animal isolation or pharmaceutical production applications. The isolator acts as a small clean room to protect what is contained within it from any type of contaminant that exists in the normal environment. In any scenario of isolator use, the cleaning of the inside is periodically needed and can often present a challenge to the user and facility. In many applications, the isolator will be sprayed with a variety of cleaning compounds and then wiped down. While the spray and wipe is better than not cleaning at all, it will rarely result in creating a sterile environment within the isolator. The best method for creating a sterile isolator before or after use is by exposing it to a true gas, such as a chlorine dioxide (CD).

One pharmaceutical company tested a chlorine dioxide gas generator for its sporicidal activity on a prototype La Calhene aseptic fill isolator equipped with two half-suits. Twenty biological indicators were used as the microbial challenge for each test.  They were placed throughout the isolator on representative surfaces such as the exhaust vent, HEPA fan grill, and accumulator.  The biological indicators were either used in their original glassine envelopes or removed from the glassine envelope and transferred into Tyvek/film pouches. The variables of humidification time, CD concentration and CD exposure time were manipulated. Charging time to an exposure concentration of 5mg/L took approximately 9 minutes. Aeration time to safe exposure levels of 0.1ppm took less than an hour. Several exposure cycles were shown to be successful using biological indicator spore strips each having a population of 106 spores. Additionally, chlorine dioxide gas penetrated into dead-leg areas and hard to reach areas of the isolator, such as deep vents, half-suit armpits and beneath other structures. Chlorine dioxide has proven itself to be a practical and effective method for disinfecting isolators as demonstrated by the high-level spore reduction.

To read this company’s isolator decontamination study in full, click here. For more about this specific application, click here.

The Influx of Influenza

It is widely known that the flu is a threat to everyone’s health.  The CDC estimates that the flu has resulted in between 9.3 million and 49 million illnesses each year in the United States since 2010¹.  We often times hear that the flu vaccine is the best approach to avoid contracting the illness, however it is not always effective.  There are two main explanations as to why the vaccine may not prevent contracting the flu.  One is the overall attributes of the person being vaccinated, such as their age and health.  The other is the correlation between the flu viruses currently in the environment and the flu vaccine currently designed to protect our population. 

Another way to eliminate the harmful influenza virus is by eliminating it from the environment through ultraviolet light (UV-C) disinfection.  With the proper dosage, UV-C kills any organism that the light shines upon.  There are even UV-C devices designed to disinfect airborne contaminants such as the influenza virus.  The Torch Aire- Recessed™ replaces a 2’x4’ ceiling tile and has the ability to disinfect up to 12,600 cubic feet per hour.  Air is pulled into the unit and passed over enclosed UV-C lamps to kill any harmful organism in seconds.  The air is then sent through a filter, trapping any large particulates before they have the chance to reenter the space.  It is perfect for any healthcare setting thanks to its ability to continuously run while the room is occupied, as well as its ease of placement and its rapid and effective performance.

Learn more about this unit, and other UV-C disinfection devices that can fit any application you may have, by contacting us here or by visiting us at APIC June 12-14 in Philadelphia at booth 1239!   

1. www.cdc.gov

The Myths and Misconceptions of Chlorine Dioxide Gas

Chlorine dioxide gas has been recognized as a disinfectant since the early 1900's, and it has been approved by the US Environmental Protection Agency (EPA) and the US Food and Drug Administration (FDA) for many applications in a variety of industries. It has been demonstrated effective as a broad spectrum, anti-inflammatory, bactericidal, fungicidal, and virucidal agent, as well as a deodorizer. Even though chlorine dioxide has been around for over a century, there is still a surprising amount of inaccurate information and misconceptions. We would like to take the opportunity to address some of those misrepresentations.

CHEMICAL PROPERTIES

Although chlorine dioxide has "chlorine" in its name, its chemistry is radically different from that of chlorine. When reacting with other substances, it is weaker and more selective, allowing it to be a more efficient and effective sterilizer. For example, it does not react with ammonia or most organic compounds. Most importantly, chlorine dioxide oxidizes products rather than chlorinating them, eliminating the formation of trihalomethanes (THMs), haloacetic acids (HAAs) and other environmentally undesirable chlorinated organic compounds.

SAFETY

The very reason decontaminating agents are used is for the purpose of killing organisms. As such, no agent can truly claim to be safe. However, chlorine dioxide gas is the safest fumigant available, due to its physical attributes and process advantages. Chlorine dioxide is not classified as a carcinogen by any health agency. Chlorine dioxide does have an odor similar to chlorine, which is beneficial because chlorine is such a recognizable smell. The odor detection level is very similar to the OSHA 8-hr safety level of .1 ppm allowing you to detect any gas leakage quickly. Cycle times are shorter with CD gas due to its faster aeration time to safe levels. This means that a potentially unsafe condition exists for a far shorter time when using CD for room decontamination.

WATER SOLUBILITY

Unlike many decontaminating agents, chlorine dioxide has the unique ability to retain its sterilization capacity in water. Chlorine reacts with water to form hydrochloric acid, but chlorine dioxide does not, maintaining a neutral pH in water. Gaseous CD is the only decontaminating fumigant that penetrates water, decontaminating both the water and the surface beneath.

MATERIAL COMPATIBILITY

The leading liquid chlorine dioxide solutions are produced through the mixing of an acid and a base. It is this acid which makes the liquid chlorine dioxide solution highly corrosive. ClorDiSys, however, does not produce chlorine dioxide gas in this same way. The method of generation ClorDiSys uses is a completely dry process where a 2% chlorine, 98% nitrogen gas flows through a matrix of sodium chlorite to produce producing 100% pure chlorine dioxide gas. The chlorine dioxide gas generated through the ClorDiSys process has an oxidation potential that is 1.5 times less that of vapor-phase hydrogen peroxide (VPHP), making it technically less corrosive. Because ours is a pure and dry process, our chlorine dioxide gas doesn’t leave a residue and does not require additional cleanup.

MORE COMMONLY USED THAN YOU THINK

Chlorine dioxide is widely used as an antimicrobial and as an oxidizing agent in drinking water, poultry process water, swimming pools, and mouthwash preparations. It is used to sanitize fruit and vegetables and also equipment for food and beverage processing. It is also employed in life science research laboratories, pharmaceutical facilities, and the healthcare industry to decontaminate rooms, passthroughs, isolators, and ductwork as well as product and component sterilization. It is also extensively used to bleach, deodorize, and detoxify a wide variety of materials, including cellulose, paper-pulp, flour, leather, fats and oils, and textiles. Approximately 4 to 5 million pounds are used daily.

Contract Sterilization

ClorDiSys Solutions offers Contract Sterilization Services where we can decontaminate your items, equipment, supplies, and products at our facility and then ship them back to you or onward to a third party. ClorDiSys utilizes chlorine dioxide gas, a US EPA registered sterilant capable of killing all viruses, bacteria, fungi, and spores. Chlorine dioxide gas is also effective against beta lactams such as Penicillins, Cephalosporins, and Carbapenums as well as amplicons and pinworm eggs. Customers can choose to single or double wrap items in Tyvek and may include biological indicators as well. Turnaround time is traditionally 24 hours, with items typically being shipped back the day after they arrive. In some cases, turnaround time can be hours, with the items arriving, being treated, and shipped on the same day. Upon completion, you will be issued a Contract Decontamination Certification Sheet describing the process and showing the sterilization cycle data.

APPLICATIONS 

• Sterilization for Non-Sterile Facilities

• Medical Devices, Instruments, HEPA and other Sterilizing Filters
• Equipment, Components, and Items entering a Clean Facility
• Tools, Computers, Printers, Keyboards, RFID Tags, Monitoring Instruments, Microscopes, Animal Cages, Shoes, and Safety Glasses
• Decontamination of Contaminated Components
• Returns from user sites, mold issues, pinworm eggs, amplicons, and beta lactams

View our sample submittal form and call the office at (908) 236-4100 with any questions.

Chlorine Dioxide: What Does it Kill?

ClorDiSys' chlorine dioxide (CD) gas is registered with the United States Environmental Protection Agency as a sterilizer (EPA Reg#: 80802-1). The US EPA defines a sterilizer as able "to destroy or eliminate all forms of microbial life including fungi, viruses, and all forms of bacteria and their spores," meaning ClorDiSys' chlorine dioxide gas will inactivate any form of antimicrobial life including spores. Spores are among the hardest organisms to kill and for this reason sterilizing agents are considered the most rigorous decontaminating agents. The difference between spore and bacterial inactivation is the same as the difference between sterilization and disinfection. CD gas is also proven effective against beta-lactams, pinworm eggs, and amplicons. Testing has been done using chlorine dioxide on a multitude of specific organism types. A table with some of the more commonly seen organisms that chlorine dioxide has been proven to eliminate can be viewed here. As testing is constantly ongoing, this is not to be thought of as a complete list of organisms in which chlorine dioxide gas is effective against. To date, no organism tested against CD gas has proved resistant.