What is plasticizer?

Plasticizers or dispersants are additives that increase the plasticity or fluidity of a plastic, especially polyvinyl chloride (PVC) tubing in computer liquid cooling. Unfortunately, the majority of plasticizing agents break down over time and under heat, thus leaching fine powder particles which are deposited on all surfaces.

Tubing with plasticizer is usually the culprit for the majority of systems failures by clogging the microchannel fins in the water block or by building upon the water pump impeller shaft thus overloading the motor.

The top photo shows a cut section of plasticizer leaching-affected PVC tubing. Photo on the bottom shows (green) dyed strains of plasticizer powder ‘gunk’ (source: overclock.net)

In the past these ‘buildup’ or ‘gunking’ issues were mistakenly attributed to pre-mixed coolants (and their glycol base) instead of tubing. Plasticizing powder, dyed by the color of the pre-mixed coolant, was leading users to the false conclusion that the coolant itself was the issue.

Cleaning the equipment, used in water loop which has been affected by this occurrence is, unfortunately, a time-consuming task: EK Water Blocks recommends taking apart all cooling equipment and cleaning it by following our cleaning guidelines. Warm soapy water and plastic q-tips for cleaning the hard-to-reach spots are a must. The affected tubing should be discarded and a fresh tube must be installed.

Preventive steps:

• Use plasticizer-free tubing only in your water cooling loop. EK-Tube ZMT (Zero Maintenance Tubing) type tubing is a EPDM rubber type tubing, has no added plasticizer and is thus safe to use. Rubber ensures great bend radius!
• As an alternative to EK-Tube ZMT type tubing EK Water Blocks recommends Primochill LRT Advanced series tubing, a market proven PVC tubing which does not suffer from plasticizer leaching. Not to be mistaken with older LRT Pro!
• If you are uncertain whether the plastic tubing contains plasticizer, it is best not to use it! As of 2013 all tubing manufactured and sold by EK Water Blocks is safe to use.