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:
- Test Strip Expiration Dates; Good Today, Dead Tomorrow? Don't toss good test strips away. Good today doesn't mean bad tomorrow.
- Diluting Chlorine, Peroxide, Quats is Easy. Dilute any concentration of disinfectant to any ppm for bottles or bucketfulls.
- What Kills Norovirus on Surfaces? Chlorine bleach works fine on any hard surface from dishes to doorknobs.
- Wash, Rinse, Sanitize: The Three Sink Method. A simple technique for kitchens anywhere.
- Chlorine Bleach Disinfectant-An Old Chemical for New Bugs. Frequent cleaning doesn't have to be expensive.
- 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.
|Effective on a wide variety of bacteria
||Can be corrosive
|Not affected by hard water
||Can be irritating to the skin
||Deteriorates over time
||Loses some activity in the presence of organic matter
|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.
- Remove test strip from vial.
- If paper, dip any end in bleach solution
- If plastic, dip pad end in bleach solution
- 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.
- Strength of your chlorine bleach (%)
- Strength you want after dilution (ppm)
- How much you need to prepare (litres, mL, quarts, cups)
- 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.