• Easy Interpretation: DISINTEK XL changes from a solid purple color to a distinct mottled or patchy appearance as the disinfectant approaches the 1.5% Minimum Effective Concentration (MEC). No subtle color changes to interpret.
• Simple, Quick Procedure: Simply dip the indicator pad in the sample for 20 seconds, and then side blot the strip. After 5 minutes examine the strip for a distinct mottled or patchy color pattern (FAIL) or a solid purple color (PASS).
• Reliable Results: The unique 20-second soaking dip insures reliable and consistent results. Never worry about using a 1.5% MEC disinfectant below its MEC.
• 100% Failure at the MEC: DISINTEK XL reliably gives the required FAIL results at glutaraldehyde levels of 1.5% or less.
• Manufactured by Serim Research specifically for Glutaraldehyde with a 1.5% MEC : DISINTEK XL is designed and tested for use with the most common 14-Day 1.5% MEC Glutaraldehyde products (Cidex and MetriCide).
• Experienced Manufacturer: Since 1988 Serim has been developing, manufacturing and marketing disinfectant tests.

QUESTION: Why do we consistently get a FAIL result well before the 14 days of use claimed for our disinfectant? We do not feel our instrument loads are excessively high!

ANSWER: Carefully read the Product Insert for the disinfectant. The inserts generally say that the disinfectant can be used up to 14 days. The actual number of days you will be able to use the disinfectant is affected by a number of factors including the number of disinfection procedures (loads), the number and type of instruments disinfected (in each load), how well the instruments are cleaned, rinsed and dried and whether you use manual (cold immersion baths) or automated instruments with or without heat. The concentration of glutaraldehyde tends to decrease over time just sitting in the bath. Dilution from poorly dried instruments, depletion due to protein and blood remaining in the instrument and heat (if used in reprocessing instruments) all add to the depletion of the glutaraldehyde concentration.

Test strips are made with the goal that they will never give a PASS result when the disinfectant is at or below the MEC. To accomplish this goal, some "False FAILS" will be seen in the concentrations between 1.5 and 2% (using the example of a 14-day glutaraldehyde with a 2.5% starting concentration and 1.5% MEC). By rejecting some solutions which may be above the MEC, you are assuring the disinfectant will never be used below the MEC.

QUESTION: We are confused by all the choices of new High-level Disinfectants and processing machines options. Is there a good information source to help us choose the best option for our facility?

ANSWER: The manufacturers of the disinfectants and reprocessing machines are the best place to start; but information is available from independent sources such as the recent article, "Disinfection of Endoscopes: Review of New Chemical Sterilants Used for High-Level Disinfection", William A. Rutala & David J. Weber Infection Control and Hospital Epidemiology, Volume 20, No. 1 January 1999, pages 69-75. Interesting information can also be found in the following Websites (Serim Research does not endorse the content of these sites nor does Serim have any relationship with these organizations. Recommendations to visit these sites are based on interesting content appearing in these sites):

1. The Q-Net (Industry news and related issues sponsored by Custom Ultra Sonics Inc.):www.myendosite.com.
2. The British Society of Gastroenterology Clinical Guidelines (Interesting reviews on a number of high level disinfection topics): www.bsg.org.uk/guidelines

QUESTION: The use instructions and timing of your strips are different than the strips I have been using. Why is there so much difference?

ANSWER: The basic chemistry and type of paper or membrane used differ significantly between test strips. Each manufacturer tests a variety of disinfectants under numerous test conditions to determine the best chemistry for their strip and the optimal procedure to get the best possible test results. Carefully read and fully understand the strip Product Insert (Directions for Use) before using a test strip. It is a good idea to run several trial tests with a new test strip and to train new personnel using Control Solutions to ensure everyone in your facility is familiar with proper test procedures and interpretation of the results. A common error is to assume that all test strips are used the same manner.

QUESTION: We use CIDEX 28-Day Glutaraldehyde Disinfectant. Does your DISINTEK XL Strip work with this product?

ANSWER: No, DISINTEK XL was developed specifically for the 14-Day CIDEX Activated Dialdehyde Solution or the 14-Day MetriCide Solution from Metrex. The Minimum Effective Concentration (MEC) for the 28- and 30-Day High Level Glutaraldehyde Solutions is typically higher (1.8-2.1%) than the 1.5% MEC commonly claimed for the 14-Day products. Surfactants are also commonly added. As a result DISINTEK XL does not work with these products. If in doubt about whether you are using the proper test strip call our Customer Service number (800-542-4670 or 1-574-264-3440) or e-mail us at customerservice@serim.com.

(Note this is not intended to be an exhaustive list of terms used in the high level disinfection field-only a brief list of terms pertinent to disinfectant testing issues)

MEC (Minimum Effective Concentration) - The percentage (%) concentration of the active ingredient in the disinfectant (or sterilant) that is the minimum concentration at which the disinfectant meets all its labeling claims for activity against target microorganisms. (Most 14 Day Reusable Glutaraldehyde products have a 1.5% MEC and most 28-30 Day Reusable Disinfectants have a 1.8-2.1 % MEC. (Refer to the disinfectant Instructional Insert or contact the disinfectant manufacturer to determine the MEC of your disinfectant and to obtain important information about other criteria and critical conditions such as temperature and contact time required to achieve High Level Disinfection.)

Chemical Indicator Strip - A test strip (like DISINTEK XL) which will indicate the approximate concentration of the active chemical ingredient in the disinfectant. Such test strips may give a PASS/FAIL Result or may be semi-quantitative (offering several color blocks which allow you to estimate the approximate level of the disinfectant). Nearly all High Level Disinfectant Chemical Indicator Strips are of the PASS/FAIL variety. Chemical Indicators cannot confirm that all instruments processed in the disinfectant solution are indeed disinfected. Chemical indicators can confirm that the disinfectant is present at levels above the MEC prior to the processing step.

Biological Indicator - A test that contains a defined quantity of live test organisms that allow the user to test the effectiveness of their disinfection system. This type of test will only confirm conditions (exposure times, temperature and disinfectant levels) are adequate in the disinfection system to achieve the level of disinfection/sterilization as indicated by the Biological Indicator. Biological Indicators cannot confirm that all instruments were completely disinfected in any given processing run only that the conditions were adequate for a properly cleaned and prepped instrument, to be exposed to adequate levels of the disinfectant.

Pre-cleaning and Rinsing - An extremely important process, by which the device or instrument to be disinfected is prepared by a cleaning procedure intended to remove as much organic debris as possible from the external and internal surfaces of the instrument. Enzymatic based cleaners are often used. These contain enzymes and detergents which help break down protein, blood, mucous or waste products which can coat the surfaces and reduce the effectiveness of the disinfectant by providing a barrier between the disinfectant and the instrument surface. Following the pre-cleaning, the instruments should be rinsed and dried as thoroughly as practical to prevent dilution from rinse liquid and premature depletion of the disinfectant by exposure to more organic matter than absolutely necessary.

High Level Chemical Disinfection - A procedure where a chemical sterilant is used for a shorter period than needed to achieve sterilization. Inactivates most micro-organisms (bacteria, viruses, fungi, microplasma) but not high levels of bacterial spores.

Use Life/ Re-Use Life (of a chemical sterilant/high level disinfectant) - The maximum length of time a disinfectant can be re-used. Established by the disinfectant manufacturer during their regulatory approval phase. While test strips are used to confirm the disinfectant remains above its MEC during the labeled Use Life, the disinfectant cannot be used beyond its labeled use life even if test strips still show PASS results.(Always refer to the Disinfectant Manufacturer’s Insert to determine the maximum Use Life).

PASS Result - A result with a chemical indicator strip which indicates that a liquid chemical sterilant/disinfectant is still above its labeled Minimum Effective Concentration (MEC). Thus it can still be used within its label claims.

FAIL Result - A result with a chemical indicator strip which indicates a liquid chemical sterilant /disinfectant is at or near its MEC. Generally a FAIL result means the disinfectant must be discarded and replaced with a fresh batch. The labeling of some disinfectants allow for retesting. Refer to the disinfectant manufacturer’s insert for instructions.