WaterCheck™ RC

Chlorine Test in Water

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watercheckrcAbout the Test

Bleach chlorine solution is commonly used as a cleansing agent to disinfect medical instruments or equipments, such as dialysis machines. After the disinfection, chlorine is then rinsed off with deionized water or RO water before the instruments can be reused. The WaterCheck RC chlorine test strip provides an easy way to monitor the chlorine concentrations during the process of disinfection.

Product Features:

1. Fast and sensitive.

  • Color reaction complete instantly to the chlorine in the sample.
  • Detect residual chlorine to less than 0.2 ppm
  • Reacts primarily with chlorine, no reaction with peroxide until it is 100 ppm or higher.

2. Very consistent

  • Consistent color reaction from lot to lot.
  • Reliable results every time and all the time

3. Easy to read colors

  • The strip color progresses from off white to very light green, green, blue, dark blue then to black/brown in response to less than 0.2 ppm trace to 500 ppm chlorine.
  • Green, blue colors are very easy to read even under poor lighting condition.

4. Residual and potency strip in one

  • The strip uses a dual indicator color system.
  • It has very broad detection range, from trace to 200 ppm and 500 ppm
  • It turns green at low chlorine levels, and blue/brown at high levels.
  • It can be used as a residual strip or a potency strip for bleach/chlorine.

5. Long shelf life, stable at room temperature

  • The dry strip is stable at room temperature.
  • The shelf life is at least 3 years from the time of manufacturing.

Simple Steps to Use

The strip is primarily designed for use in hemodialysis disinfection control. However, it can also be used in different applications.

For disinfection of dialysis machines, bicarbonate mixing tanks or water distribution system, the final rinse water should have none or less than 0.5 ppm of residual chlorine according to the AAMI standards. The simple strip test can verify the compliance of the water quality.

  • Collect the test sample in a clean cup from the sample port according to the manufacturer of the dialysis system.
  • Dip the strip in the test solution for one second.
  • For midstream sampling, wet the strip in the stream of test water briefly.
  • Gently shake off the excess water.
  • Compare the strip color to the color chart on the label.
  • Any trace of green color is an indication of the presence of residual chlorine.

How to Interpret the Test Results

Interpretation of the test results depends on the nature of the testing.

Using the one second dip-and-read test procedure, the strip can detect as low as 0.2 ppm of residual chlorine and will show a recognizable green color. Although the maximal allowable residual chlorine contaminant level in the rinse water is 0.5 ppm by AAMI standards, in practice, all rinse water in hemodialysis setting is tested negative with the strip. If tested positive, the rinsing should be continued.

If measurement of a more accurate chlorine level is desired, a 5 second test procedure should be followed by holding the strip under a slow running test water for 5 seconds and comparing the strip color with the color chart immediately. The strip color will be intensified at the end of 5 seconds. The length of the contact time of the strip with fresh test sample determines the final intensity of the strip color. The longer the contact time, the darker the strip color will be. The actual strip color may vary depending on how the test is done and the lighting condition of the room. The residual color blocks on the label are standardized with the 15 second test procedure and is considered semiquantitative only.

Types of Samples

The strip is the most commonly used in detecting chlorine in water. However, the strip can also be used for detecting chlorine in other media, such as dialysate or bicarbonate solutions. In the blood, plasma or serum, chlorine will reacts with blood components such as ascorbic acid or other antioxidants, also with serum proteins and reduce the detectable chlorine level. What is detected in such media is the remaining of the chlorine rather than the initial level of chlorine contamination. In solvents or oil, the presence of chlorine can also be detected by the strip. However, the results should only be interpreted as qualitative.

How to Chose the Right Chlorine Test Strip for Your Specific Application

Since the test is based on the oxidative election transfer of chlorine molecules, chlorine will reacts to a variety of indicator system with different chemical properties. Because of this, not all the chlorine tests are created equal even when the same chemical indicator is used. They all differ in detection sensitivity, detection range, chemical specificity and thermal stability.

IBT offers three chlorine test strips for different applications. The following table compares the main features and the suggested applications of each strip.

Product Name
Catalog Number
Main Features Suggested Applications
WaterCheck RC
RC22101

Residual Chlorine / Bleach0.2 ppm up to 500 ppm

Not interfered by low level of peroxide.

Not affected by peracetic acid in the air.

Routine use for monitoring rinse water quality.Comply with AAMI standards of 0.5 ppm or less.

Verify 500 ppm Bleach

Not recommended for 0.1 ppm chloramine testing

WaterCheck CP
CP20101

Residual Chlorine/Bleach0.2 ppm up to 5000 ppm

Equally sensitive for peroxide, peracetic acid.

Sensitive to a broad spectrum of peroxides, chromate and other oxidants.

Routine use for monitoring water qualityComply with AAMI standards of 0.5 ppm or less for rinse water.

Final check for dialysate contamination

Best for broader protection of patient safety

Not recommended for 0.1 ppm chloramine testing

WaterCheck CM
CM20201

Low Level Chlorine/ChloramineSpecially for detection of chloramine 0.1 ppm or less

Comply with AAMI standards for purified water

Detect both chlorine and chloramine

Monitor carbon tank water purification loop.Check to assure the acute mobile unit water quality of none or not more than 0.1 ppm of total chlorine

There are many other test strips which will react with chlorine but lack the sensitivity required for hemodialysis or other critical quality water applications. For detailed explanation, refer to the IBT Bulletin #402 “The Most Commonly Misused Chlorine Test Strips”

Ordering Information

Product Availability

The WaterCheck RC test strips are packaged 100 strips in a bottle and 6 bottles in a box.

Cat. No. Description
RC22101 Single bottle of 100 strips
RC22101-6 6 bt/pk (600 strips)


Ordering Information

Order by phone, fax or email.

Contact our Customer Service for more information or technical support.

Customer Service:
Tel: 574-264-0025
1-800-490-5500
Fax: 574-264-2787
email: ibtbiomed@earthlink.net

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