Chlorine/Iodine Test Strips

Choose from 7 Indigo® chlorinee & iodine test strips for your water treatment, food handling, daycare, healthcare, medical device sanitizing and disinfection needs. All come with 100 test strips/vial, a guaranteed 3 year minimum shelf life. Full documentation is available including a Stability Statement, Certificate of Analysis & SDS. Optional next day delivery in any quantity of most items. Buy Indigo® test strips, the brand you can trust for accuracy & technical support. Call us on our toll free line for immediate assistance or e-mail us with your questions. 1 hour response is typical during business hours, M-F, slightly longer on weekends.

Indigo® Chlorine Test Strips

Hypochlorites are the most used of the chlorine based disinfectants. They have a broad range of antimicrobial action, are unaffected by water hardness, are economical & fast acting. They are most effective in the pH 5-7 range

Organic matter in the form of serum, blood, pus, or fecal material can interfere with the antimicrobial activity of chlorine and iodine based disinfectants & can result in low or no killing power.

This problem is most common in hospitals and long term care facilities and may require much higher disinfectant concentrations. Higher than normal concentration of hypochlorite needed to overcome this can be confirmed up to 10000ppm with Indigo® chlorine test strips.

Indigo® chlorine test strips measure concentrations ranging from residual to high levels needed for applications ranging from water treatment to biofilms to medical devices. Documentation for healthcare quality assurance certification includes Certificates of Analysis, Stability Statements and Safety Data Sheets (SDS). All strips meet or exceed a minimum 3 year guaranteed shelf life.
Displaying 1 to 7 (of 7 products)
200ppm Total Chlorine

200ppm Total Chlorine

SKU: 33815-200
$2.55USD or lower Each
300ppm Free Chlorine

300ppm Free Chlorine

SKU: 33815-300
$8.95USD or lower Each
1000ppm Free Chlorine

1000ppm Free Chlorine

SKU: 33815-1000
$14.95USD or lower Each
2000ppm Free Chlorine

2000ppm Free Chlorine

SKU: 33815-2000
$14.95USD or lower Each
10000ppm Free Chlorine

10000ppm Free Chlorine

SKU: 33815-10K
$21.95USD or lower Each
0-10ppm Residual Chlorine

0-10ppm Residual Chlorine

SKU: 33815-10
$21.95USD or lower Each
50ppm Iodine Test Papers

50ppm Iodine Test Papers

SKU: 33815-I
$2.95USD or lower Each
More Information
The biochemical mechanisms for chlorine's microbiocidal properties are not well understood. They range from breaking disulfide bridges between cysteines in enzymes, decreased ATP production to breaks in DNA.

Most chlorine based compounds are fast acting microbicides but they work best when pH is between pH5-8 which is mildly acidic to mildly alkaline.

Effectiveness of hypochlorites (chlorine bleach) solutions are reduced in the presence of organic compounds such as blood and feces.

Documentation for healthcare quality assurance certification includes Certificates of Analysis, Stability Statements and Safety Data Sheets (SDS). All strips meet or exceed a minimum 3 year guaranteed shelf life. Our records though indicate a 5 year shelf life or more is typical.

Additional material that may interest you:
  1. Test Strip Expiration Dates; Good Today, Dead Tomorrow? Don't toss good test strips away. Good today doesn't mean bad tomorrow.
  2. Diluting Chlorine, Peroxide, Quats is Easy. Dilute any concentration of disinfectant to any ppm for bottles or bucketfulls.
  3. What Kills Norovirus on Surfaces? Chlorine bleach works fine on any hard surface from dishes to doorknobs.
  4. Wash, Rinse, Sanitize: The Three Sink Method. A simple technique for kitchens anywhere.
  5. Chlorine Bleach Disinfectant-An Old Chemical for New Bugs. Frequent cleaning doesn't have to be expensive.
  6. Chlorine Test Strips-Daycare Disinfection Checklist. Common & not so obvious things to disinfect not only in daycare but office, business or home.

Indigo® Chlorine Test Strip Technical Specifications

  • 0 to 10ppm (available): 0-0.5-1-3-5-10ppm; read results in 30 seconds
  • 0 to 200ppm (total): 10-50-100-200ppm; read results in 1 second
  • 0 to 300ppm (available): 0-25-50-100-200-300ppm; read results in 5-10 seconds
  • 0-1000ppm (available): 0-50-100-250-500-1000ppm; read results immediately
  • 0-2000ppm (available): 0-25-50-200-500-800-1500-2000ppm; read results in 60 seconds
  • 0-10000ppm (available: 0-1000-2500-5000-7500-10000ppm; read results in 10 seconds

Sodium Hypochlorite Pros & Cons

Chlorine (sodium hypochlorite) is an sanitizing/disinfecting chemical for hard surfaces where food is prepared. Iodine, also a halogen, is listed below but is used relatively rarely by comparison.


Pros Cons
Effective on a wide variety of bacteria Can be corrosive
Not affected by hard water Can be irritating to the skin
Generally inexpensive Deteriorates over time
  Loses some activity in the presence of organic matter


Pros Cons
Not affected by hard water Effectiveness decreases greatly with increase in pH
Less irritating to the skin than chlorine Should not be used in water > 50°C
Activity is not lost rapidly in the presence of organic matter May also discolor equipment and surfaces
Chlorine use in sanitation and disinfection has rare cases of serious toxicity but careful handling is nevertheless recommended. Fumes from undiluted household bleach can cause eye irritation. Ingestion can cause oropharyngeal, esophageal & gastric burns. Consult first aid instructions on bleach container & seek medical aid if necessary.

How to Use Chlorine Test Strips?

Instructions for chlorine/chlorine dioxide/iodine test strip use is the same regardless of concentration range.
  1. Remove test strip from vial.
  2. If paper, dip any end in bleach solution
  3. If plastic, dip pad end in bleach solution
  4. Remove and compare to color chart. Times vary-see individual strips for specifics.

How to Dilute Chlorine & Iodine

The color charts on chlorine (hypochlorite) and iodine solutions indicate concentrations from 5ppm up to 10000ppm. 
Use our chlorine bleach ppm dilution calculator to take the guesswork out of making up accurate sanitizer solutions.

Simply enter:
  1. Strength of your chlorine bleach (%)
  2. Strength you want after dilution (ppm)
  3. How much you need to prepare (litres, mL, quarts, cups)
  4. Press "Calculate"
It will tell you how much undiluted chlorine bleach to mix with water. Confirm solutions are in the correct range with the appropriate Indigo® test strip.

You can also prepare calibration solutions for your test strips to confirm they can still be used past their expiration date. Do this only with freshly opened concentrates. You may find one of our graduated cylinders & graduated medicine droppers useful for this.