Residual Chlorine

Health Hazards (Long-term and Chronic)

• Affects Taste and Odor: Residual chlorine causes tap water to have an unpleasant “bleach-like” or “chemical” taste and odor, which affects the desire to drink and the original flavor of food.
• Irritation to the Body: When bathing with water containing residual chlorine, the chlorine evaporates into chlorine gas when heated, accumulating in the closed space of the bathroom and irritating the respiratory system (especially for asthma patients and children). At the same time, residual chlorine strips moisture from the skin and hair, causing dryness, itching, and damage to hair quality.
• Disrupts Gut Microbiota: Long-term consumption of water with residual chlorine may indiscriminately kill beneficial bacteria in the gut, potentially affecting digestive health.
• Potential "Three Causality" Risks (Controversial but of High Consumer Concern): This is the most worrying aspect. When residual chlorine reacts with natural organic compounds in the water (like humic acid and fulvic acid), it forms disinfection by-products (DBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs). These substances are classified by the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) as potential carcinogens, teratogens, and mutagens. Although the levels of these substances in tap water are strictly controlled, the cumulative risk of long-term intake is something people want to avoid.
  
  

Impact on Quality of Life

• Damages Food Nutrients: Using chlorinated water to wash and cook food (such as vegetables and fruits) may destroy the vitamins and other nutrients on their surface.
• Damages Clothing: Chlorinated water can oxidize clothing fibers, leading to the fading and aging of brightly colored clothes, and yellowing and graying of white clothes.
  
  

Impact on the Water Purifier Itself (Very Important!)

• The #1 Killer of RO Membranes: For water purifiers that use reverse osmosis (RO) technology, residual chlorine oxidizes and irreversibly degrades the polyamide desalination layer on the surface of the RO membrane, causing a rapid decline in desalination performance (increased TDS value of purified water), reduced water production, and significantly shortening the lifespan of the RO membrane. Protecting the RO membrane from residual chlorine is one of the core tasks of the pre-filter.
  
  

How Do Water Purifiers Remove or Mitigate the Harm of Residual Chlorine?

Core Solution: Activated Carbon Adsorption (Most Common and Effective)

• Principle: Activated carbon has a highly developed porous structure and a large specific surface area (one gram of activated carbon has a surface area equivalent to the size of a soccer field). It acts like a "magnet" to physically adsorb residual chlorine molecules in the water. Additionally, the surface of activated carbon can catalytically reduce residual chlorine (Cl₂, HClO) to non-toxic chloride ions (Cl⁻).
• Forms:
  
  
  • Granular Activated Carbon (GAC): Loose carbon particles with strong adsorption ability, but water flow can easily short-circuit.
  • Compressed Activated Carbon (CTO): Activated carbon powder is high-pressure sintered into a solid filter core, which has a tighter structure. Water must flow through the carbon block, resulting in more thorough filtration and better performance. This is the form used in your product.
• Position: As a pre-filter, it is installed before the RO membrane. Its primary task is to protect the subsequent RO membrane and improve taste.
  
  

Ultimate Solution: Reverse Osmosis (RO) Technology

• Principle: The pore size of the RO membrane is extremely small (0.0001 microns), and the volume of residual chlorine molecules, as well as the disinfection by-products (such as THMs) generated by the reaction of residual chlorine with organic substances, is much larger than water molecules. Therefore, they are almost 100% blocked and removed by the RO membrane.
• Position: As the core purification unit. After passing through the RO membrane, residual chlorine and its by-products are completely removed from the water.
  
  

Other Auxiliary or Alternative Solutions

• Vitamin C Filtration: Some high-end filters add vitamin C to neutralize residual chlorine through a chemical reaction, but this is more expensive and is more commonly found in beauty showerheads.
• KDF (Kinetic Degradation Fluxion): A high-purity copper-zinc alloy that effectively removes residual chlorine through electrochemical oxidation-reduction reactions while inhibiting bacterial growth. It is often used in combination with activated carbon.