• Swimming pool sanitizer in slow-dissolving tablet (puck) form
• Active ingredient is trichloro-s-triazinetrione at 99% w/w — a chlorinated isocyanurate, so it contributes cyanuric acid (stabiliser) to the water as it dissolves
• Low water solubility (1.2 g/100 g at 25°C) — designed for feeding through a skimmer, floater or automatic chlorinator rather than broadcast dosing
• Acidic in solution (pH 2.8)

Water chemistry target

Regal®’s Canadian Pool Care Guide states: “A free chlorine level of 1-3 ppm should be maintained in the pool at all times.”

Safety, handling and storage (from the Regal Elite Chlor Pucks Canadian Safety Data Sheet, issued 23 April 2024)

• Signal word: DANGER. H272 — May intensify fire; oxidizer. H302 — Harmful if swallowed. H314 — Causes severe skin burns and eye damage. H318 — Causes serious eye damage. H335 — May cause respiratory irritation. H410 — Very toxic to aquatic life with long lasting effects.
• Wear protective gloves, protective clothing, eye protection and face protection. Do not breathe dust or fume. Do not eat, drink or smoke when using this product.
• Storage: “Keep product in tightly closed container when not in use. Store in a cool, dry, well-ventilated area away from heat or open flame. Do not store with water, oxidizing agents, alkalies, grease, reducing agents and acids. Keep out of reach of children.” Do not store at temperatures above 140°F (60°C).
• Incompatible materials: acid, alkali, other chlorine agents, oils/fats and flammable materials. Never mix this product with any other pool chemical — including other chlorine products — and never allow it to become wet in storage.
• Keep away from heat, hot surfaces, sparks, open flames and other ignition sources, and away from clothing and other combustible materials.