Sodium Dichloroisocyanurate (SDIC) is a highly efficient, broad-spectrum, fast-acting biocidal disinfectant and bleaching agent. Structurally stabilized by a cyanuric acid ring, it retains its active chlorine content far better under sunlight and heat compared to traditional liquid sodium hypochlorite (bleach) or calcium hypochlorite.
It is widely produced in two distinct chemical types: Anhydrous and Dihydrate. Below is the benchmark product specification sheet for commercial-grade SDIC.
1. General Identification
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Chemical Name: Sodium Dichloroisocyanurate / Sodium Troclosene
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Synonyms: SDIC; Diclosan; Isocyanuric Acid Sodium Salt
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CAS Number: 2893-78-9 (Anhydrous) / 51580-86-0 (Dihydrate)
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Molecular Formula: C3Cl2N3NaO3
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HS Code: 2933.6929.00
2. Technical Specification Parameters
| Parameter / Index | SDIC Anhydrous Specification | SDIC Dihydrate Specification |
| Appearance | White crystalline powder, granules, or tablets | White crystalline powder, granules, or tablets |
| Available Chlorine Content | 60.0% | 55.0% – 56.0% |
| Moisture / Water Content | 3.0% | 11.0% – 14.0% |
| pH (1% aqueous solution) | 5.5 – 7.0 | 5.5 – 7.0 |
| Solubility (at 25°C) | 25 g / 100 g water | 28 g / 100 g water |
| Matter Insoluble in Water | 0.1% | 0.1% |
| Granule Mesh Sizes (Typical) | 8–30 mesh, 20–60 mesh | 8–30 mesh, 20–60 mesh |
| Tablet Weights (Custom) | 1g, 2g, 3.3g, 20g, 200g | 1g, 3.3g, 20g |
3. Physical Form Variants & Applications
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Powder: Primarily used for chemical compounding, rapid shock-treatment of water, and formulation of industrial sanitizing detergents.
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Granular: Highly favored for direct application in swimming pools and cooling tower basins because it sinks cleanly and dissolves quickly without clouding the water.
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Tablets: Widely used in drinking water purification (effervescent tablets), hospital surface disinfection, and household sanitation due to precise dosing control.
4. Key Performance Advantages
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Neutral pH Profile: Unlike highly alkaline liquid bleach or highly acidic alternatives, a 1% solution of SDIC sits near-neutral (5.5 – 7.0). This significantly reduces equipment corrosion risks and keeps the chlorine in its most active biocidal state: hypochlorous acid (HOCl).
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Cyanuric Acid Stabilization: The release mechanism provides inline stabilization, safeguarding the active chlorine from UV degradation in outdoor settings (like open cooling towers or pools).
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Excellent Solubility: Leaves zero lime scale or chalky sludge behind, keeping filter systems clean.
WARNING: UN 2465 Oxidizing Solid
SDIC is a powerful oxidizing agent. It must be kept completely dry during storage. If exposed to small amounts of moisture or mixed with acids, it can undergo exothermic decomposition, releasing toxic, highly reactive chlorine gas. Store exclusively in original HDPE drums away from organic matter or combustible materials.