Chlorophenol Red Test Paper

Chlorophenol Red Test Paper

  • Available in sheets
  • Additional sizes available upon request
  • Bulk quantities available
  • Sealed in shrink-wrap or envelope

Product Description

Chlorophenol Red Test Paper

Chlorophenol Red (CPR) test paper is useful in differentiating between a solution with an acidic pH and one with a more neutral pH. The unreacted paper is yellow/orange in color. At neutral pH (about 6.7) the paper will turn a reddish color. At higher pH values, the paper will turn more violet. Given that the paper starts out yellow/orange and turns red at roughly the pH of water, it is useful in finding water leaks.


  1. Remove one Chlorophenol red test paper sheet from the packaging, being careful not to touch the sheet anywhere other than where you grasp it.
  2. Dip the sheet into the solution to be tested for 1-2 seconds and remove. Alternatively, place the test sheet near a seal where you suspect there might be a leak. Note: Do not dip the sheet directly into a solution that may later be consumed. Always test a sample of the solution and discard it when finished.
  3. The test paper will turn red/violet in seconds if dipped into a solution that is neutral (pH ~ 7) or basic (pH >7).

NOTE: The solution must be water-based.

Disclaimer: Precision Laboratories products are not approved for use as medical devices. Products and product information is for informational purposes only and not intended for use to diagnose, treat, cure or prevent any medical condition. Consult a medical doctor when needed.


Additional Information


3 Years Minimum

Item # (1):

240-24-810 (24 sheets, 8″ x 10″ [200mm x 250mm])

Item # (2):

240-500-810 (500 sheets, 8″ x 10″ [200mm x 250mm])


Additional sheet sizes available upon request

Product Documentation