Combined Chlorine
Chlorine that has reacted with contaminants and is no longer effective for sanitization.
Definition
Combined chlorine (CC) is the difference between total chlorine and free chlorine. It consists primarily of chloramines — compounds formed when chlorine reacts with ammonia, urea, and other nitrogen compounds from bathers. Chloramines are responsible for the "pool smell," eye irritation, and respiratory irritation often mistakenly blamed on too much chlorine. When CC exceeds 0.5 ppm, breakpoint chlorination (shock treatment) is required.
Quick Facts
- Ideal Range
- 0–0 ppm
- Units
- ppm
- Also Known As
- CC, combined chlorine, chloramine, chloramines, bound chlorine, combined available chlorine
The source below directly defines combined chlorine as CC = TC - FC and states its own state pool code requires breakpoint superchlorination when combined chlorine reaches 0.5 ppm -- both figures above match this exactly.
Sources
- How To Shock The Pool (Chlorinate To Breakpoint) — Indiana Department of Health, Environmental Public Health Division (Government / public health authority)
Relationships
Outgoing Relationships
- causes → Strong Chlorine Smell
- causes → Eye Irritation
- causes → Skin Irritation
- measured by → Water Testing
- part of → Total Chlorine
- explained by → glossary/combined-chlorine
- related to → Breakpoint Chlorination
Incoming Relationships
- compared with ← Free Chlorine
- related to ← Breakpoint Chlorination
- related to ← Indoor Pool
- causes ← Strong Chlorine Smell
- related to ← Eye Irritation
- related to ← Skin Irritation