The "New" Pollutants: Short-Chain PFAS in Urban Tap Water

As older "long-chain" chemicals (PFOA/PFOS) are phased out, industries have switched to "short-chain" versions like PFBA and PFHxA. These are proving to be a nightmare for Malaysia’s current water infrastructure.

• Why they are harder to catch: If a filter is like a fishing net, long-chain PFAS are "big fish" that get caught easily. Short-chain PFAS are like tiny minnows—they are so small and travel so fast through water that they swim right through standard sand and chlorine filters used in most Malaysian treatment plants.

• The Filtration Gap: Studies in 2025 confirmed that Granular Activated Carbon (GAC)—the standard in high-end municipal and home filters—is 50% less effective at stopping short-chain chemicals. These chemicals stay dissolved in the water all the way from the treatment plant to urban kitchen taps in Kuala Lumpur, Putrajaya, and Subang Jaya.

• The RO Requirement: This has led to the 2026 expert consensus that Reverse Osmosis (RO) is the only "fail-safe" solution. RO membranes have pores so small (0.0001 microns) that they physically block even the smallest PFAS molecules.

Reference: 
Assessing the Effectiveness of Point-of-Use Residential Drinking Water Filters for PFAS (ACS Publications 2025) 

Researchers investigate a new method to detect short-chain PFAS (NIEHS 2025).