Jim Perry, Senior Marketing consultant, Water Hygiene Centre explores how jointing compound might impression water methods.
Plumbing jointing compounds (or pastes as they’re also referred to as) have been a trusted a part of water system set up observe for many years, which is utilized to the threads of compression fittings to create a watertight seal, these jointing compounds nonetheless stay extensively utilized in home cold and hot water methods, business buildings, and healthcare environments.
As requirements evolve and our consciousness of water security improves, so too should our strategy to those jointing compounds. Over current years there have been modifications to WRAS (Water Laws Advisory Scheme) testing and certification for these merchandise, alongside some considerations about potential bacterial contamination points linked to compound overuse, that means that installers and undertaking / property managers should now suppose extra fastidiously than ever about product choice and software.
This article explains what has modified and why figuring out precisely what jointing compound is getting used on a home scorching and chilly water system issues for compliance, efficiency, and public well being.
WRAS Testing: From 85°C to 23°C. What’s Modified?
For a few years, WRAS approval testing for jointing compounds was carried out at as much as 85°C, a temperature chosen to replicate typical home scorching water methods, this assured installers {that a} product authorized by WRAS was secure for contact with potable water in each cold and warm methods. Nevertheless, WRAS’s testing laboratory has now revised its testing methodology, decreasing the take a look at temperature to 23°C.
This shift aligns with European commonplace testing protocols, which historically makes use of room temperature situations when assessing whether or not any substances might migrate into ingesting water.
Does this imply WRAS authorized compounds are not appropriate for decent water?
Not essentially, as the important thing distinctions are:
– WRAS approval confirms water security at room temperature
– The producer should verify temperature suitability for decent water (nonetheless, might refer again to the WRAS approval).
Taking the above on board, this implies installers should test the technical information sheet and to not simply depend on a WRAS badge to verify most really helpful working temperature.
Why the change issues
Some water methods akin to these in healthcare function underneath strict management necessities / regimes outlined in paperwork akin to HTM:04-01.
Utilizing the fallacious product in a healthcare setting may:
– breach compliance necessities
– compromise water high quality
– create danger for susceptible sufferers
So, the WRAS adjustment isn’t a limitation, however a mild reminder that approvals and temperature rankings should be checked collectively.
Different Related Approvals: BS 6920 / KIWA / NSF
WRAS shouldn’t be the one certification to assessment or contemplate when selecting jointing compounds:
| Approval | What it Confirms | Why it Issues |
| BS 6920 | Product is chemically secure when in touch with ingesting water. | Protects style, odour, color, and water chemistry. |
| KIWA | Meets strict European water security and stability requirements. | Important for international and high-specification tasks. |
| NSF | Worldwide potable water security certification. | Recognised globally throughout business sectors. |
Merchandise supported by a number of certifications have the potential to offer stronger assurance of long-term security, particularly the place uncompromised water high quality in high-risk areas is paramount.
The hidden concern: overusing jointing compounds
Jointing compounds can work nicely when utilized appropriately, however overuse / software is usually a widespread and expensive mistake, which might result in critical water high quality issues.
What goes fallacious when an excessive amount of compound is utilized:
– It has the potential to be pushed into the pipework throughout tightening
– The surplus travels via the system
– It might accumulate in valves, strainers, aerators, or filters
– The place the compound is captured, it could present an space for biofilm formation which might result in microbial progress / contamination
– Restriction in move the place the compound has settled in valves, strainers, aerators, or filters.
In extreme instances, this may:
– Cut back operational efficiency
– Trigger valve malfunctions
– Improve upkeep for cleansing
– Compromise total water high quality, resulting in adversarial microbiological pattern outcomes.
Greatest observe software (if required as a final resort)
A secure and hygienic set up requires:
– A skinny, even software solely on male threads
– Avoiding smearing compound into fittings or pipes
– Submit-installation flushing (with no restrictions i.e., filters, strainers in place) to clear any residue
– Choosing solely the quantity of compound that required to finish the duty.
If compound squeezes out when tightening a becoming it’s evident that an excessive amount of compound has been used.
Why some material consultants advocate decreasing or avoiding use:
Because of the potential water high quality considerations, it has change into obvious in undertaking specs that using jointing compounds is to be prevented wherever attainable, particularly in water methods containing:
– Thermostatic Mixing Valves / Faucets (TMVs / TMTs)
– Advantageous strainers (e.g., inline Y-strainers)
– Faucet filters / aerators.
Options embrace, however not restricted to:
– PTFE (Teflon) tape or twine
– Pre-formed sealing washers (Non EDPM).
The above choices create an efficient seal with out introducing extreme particles into the home water methods, with the under outcomes:
– Lowered danger of bacterial progress
– Longer system lifespan
– Simplified compliance
– Decrease upkeep and callouts
Abstract
Jointing compounds might stay an essential a part of plumbing observe, however their use should be smarter and higher knowledgeable than beforehand. The WRAS take a look at temperature change from 85°C to 23°C doesn’t prohibit scorching water use; as a substitute, it emphasises the accountability of installers to confirm suitability and prioritise system hygiene.
By guaranteeing the proper product selection, utilizing minimal portions, and exploring safer alternate options the place acceptable, we are able to defend each the water system efficiency and public well being, together with the security of the tip consumer from any potential an infection points.
* The knowledge offered is from a weblog on the Water Hygiene Centre web site. It is appropriate as of the date of unique publication – November 2025.
Picture: Water Hygiene Centre