A reverse osmosis system removes chlorine effectively, and it is worth being precise about which part does it, because the answer determines what you have to maintain. It is not the membrane. The carbon cartridges ahead of the membrane do that job, and they do it out of necessity rather than as a bonus feature.
Why the membrane cannot do it
Thin film composite membrane material is degraded by chlorine, steadily and irreversibly. A membrane exposed to chlorinated water loses its rejection ability over a fairly short period, which shows up as rising dissolved solids in the treated water long before anything else changes. That is why every reverse osmosis system has carbon stages in front of the membrane: they are not there to improve the taste, they are there to keep the membrane alive.
What that means for maintenance
The carbon pre filters are the most consequential cartridges in the system, and their exhaustion is invisible. Chlorine removal consumes carbon chemically and expires with no discoloration and often no change in taste, because the last of a spent bed still handles the taste threshold after it has stopped removing the bulk. So a system with pre filters years overdue is putting chlorine onto the membrane continuously, and the eventual cost is a membrane rather than a cartridge.
Chloramine, the harder case
Many utilities dose chloramine rather than free chlorine, because it is deliberately more stable and survives further into the distribution network. Standard carbon handles it poorly, needing several times the contact, so a system fitted with ordinary carbon on a chloramine supply is passing chloramine to the membrane while appearing to work. Catalytic carbon is the correct media there. Check what your utility uses: the EPA requires every community water system to publish an annual Consumer Confidence Report naming the disinfectant, and maintains a finder.
Confirming it is working
Test the water between the carbon stages and the membrane if the system allows it, or at minimum test the treated water at the faucet with a chlorine test, since any detectable chlorine there means the carbon is spent and the membrane is being damaged. Change cartridges on stated volume and note the date on each housing. And take feed and permeate readings periodically to watch membrane condition. Our softener cost guide covers whole house chlorine removal as an alternative.
Questions people ask about does ro remove chlorine
Does the membrane remove chlorine?
No. The carbon stages ahead of it do, and they must, because chlorine degrades thin film composite membrane material.
What happens if the carbon is spent?
Chlorine reaches the membrane and destroys it steadily, so the eventual cost is a membrane rather than a cartridge.
Does it work on chloramine?
Standard carbon handles chloramine poorly. Catalytic carbon is needed where the utility doses chloramine rather than free chlorine.
How do I check the carbon is still working?
Test the treated water at the faucet for chlorine. Any detectable chlorine there means the carbon is spent.