GUARDIAN™ Quick Dip Residual Chlorine (5212)

The GUARDIAN™ Quick Dip Residual Chlorine (5212) is a semiquantitative reagent test strip that detects free chlorine levels in water used to rinse dialysate lines after hemodialysis equipment disinfection. The device consists of a chemically treated 0.20-inch square pad affixed to a 3.25-inch polystyrene strip that produces yellow-green color when exposed to chlorine, with color intensity proportional to free chlorine concentration (0–5 ppm).

Both the subject and predicate devices are semiquantitative paper indicator strips on plastic handles that measure free chlorine by oxidizing a redox indicator. The key difference is the test method: the subject device requires a 2-second dip and gentle shake with color comparison within 5 seconds, whereas the predicate requires 30 seconds vigorous movement and comparison within 10 seconds. Color development differs (subject: yellow/shades of green; predicate: white/shades of purple), but both achieve identical color blocks at 0, 0.5, 1.0, 2.0, and 5.0 ppm.

Not stated in this summary.

The GUARDIAN™ Quick Dip is substantially equivalent because it has the same intended use as the predicate device (detecting residual chlorine in dialysis rinse water), uses the same chemistry (redox indicator), measures the same analyte (free chlorine), and demonstrates equivalent performance across the same concentration range (0–5 ppm). Non-clinical testing shows the subject device meets reference values, meets stability requirements, and has no new safety or effectiveness concerns. The simplified test procedure and different color chemistry do not raise new safety questions.