1,3-dichloro-5,5-dimethylhydantoin

CAS: 118-52-5

Overview

1,3-Dichloro-5,5-dimethylhydantoin (CAS 118-52-5 ), commonly known as DCDMH or by trade names such as Dactin and Halane, is a solid chlorine-donor compound used industrially as a controlled-release biocide and bleaching agent.

Unlike liquid chlorine sources, it delivers active halogen in a stable, measurable form suited to demanding process environments. In water treatment, DCDMH controls microbial growth in cooling towers and industrial process water.

It functions by releasing available chlorine at a controlled rate for swimming pools and systems. Pulp and paper manufacturers use it as a bleaching agent to achieve consistent whiteness targets without handling risks.

This chemical avoids the dangers of gaseous chlorine while maintaining high efficacy. In personal care formulations, it functions as a preservation booster and antimicrobial active in various rinse-off products.

It is particularly useful where residual biocidal activity is required for safety. Food processing facilities apply it as a sanitizing agent for equipment and surface disinfection within strict regulatory limits.

DCDMH is supplied as a white crystalline powder, granules, or pressed tablets depending on the application. Standard grades include technical and water treatment quality for diverse industrial needs.

Specifications are typically aligned to active chlorine content and moisture limits for stability. Packaging ranges from small drums to bulk quantities to accommodate both formulation-scale and industrial requirements.

Physical Properties

Melting Point	132 °C
Boiling Point	214.7±23.0 °C(Predicted)
Density	1.5 g/cm³ @ Temp: 20 °C
Flash Point	171 °C
Appearance	Powder
Color	White
Form	Crystalline Powder
Water Solubility	0.21 g/100 mL (25 ºC)
Vapor Pressure	0.003Pa
Refractive Index	1.5720 (estimate)
pH	4.4 (H2O)(HSDB)
Log P	-0.94

Safety & Handling

Danger GHS03 GHS05 GHS07 GHS08 GHS09 Hazard Statements H272 May intensify fire; oxidizer H302 Harmful if swallowed H314 Causes severe skin burns and eye damage H315 Causes skin irritation H317 May cause an allergic skin reaction H319 Causes serious eye irritation H333 May be harmful if inhaled H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled H335 May cause respiratory irritation H400 Very toxic to aquatic life H410 Very toxic to aquatic life with long lasting effects Precautionary Statements P210 Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking. P220 Keep away from clothing and other combustible materials. P233 Keep container tightly closed. P260 Do not breathe dust/fume/gas/mist/vapours/spray. P261 Avoid breathing dust/fume/gas/mist/vapours/spray. P264 Wash … thoroughly after handling. P270 Do not eat, drink or smoke when using this product. P271 Use only outdoors or in a well-ventilated area. P272 Contaminated work clothing should not be allowed out of the workplace. P273 Avoid release to the environment. P280 Wear protective gloves/protective clothing/eye protection/face protection. P284 In case of inadequate ventilation wear respiratory protection. P316 Get emergency medical help immediately. P319 Get medical advice/attention if you feel unwell. P321 Specific treatment (see … on this label). P330 Rinse mouth. P363 Wash contaminated clothing before reuse. P391 Collect spillage. P403 Store in a well-ventilated place. P405 Store locked up. P501 Dispose of contents/container in accordance with local regulations. P264+P265 Wash … thoroughly after handling. P301+P317 Get emergency medical help. P302+P352 IF ON SKIN: Wash with plenty of water. P304+P317 Get emergency medical help. P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing. P332+P317 Get emergency medical help. P333+P317 Get emergency medical help. P337+P317 If eye irritation persists: Get medical advice/attention. Get emergency medical help. P342+P316 Get emergency medical help immediately. P362+P364 Take off contaminated clothing and wash it before reuse. P370+P378 Use … for extinction. P403+P233 Store in a well-ventilated place. Keep container tightly closed. P301+P330+P331 Rinse mouth. Do NOT induce vomiting. P302+P361+P354 IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower. P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. P305+P354+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code	29332100
UN Number	1479
ADR Class	5.1
Packing Group	II
Storage Class	5.1B - Oxidizing hazardous materials
WGK (Germany)	3

Other Names

Industries

Personal Care & Cosmetics Food & Nutrition Pulp & Paper Water Treatment