What Is a Safe PTV (Pendulum Test Value)?

A safe PTV, or Pendulum Test Value, is generally 36 or above, based on HSE-recognised
guidance for slip resistance. A reading in this range indicates low slip risk under the specific
conditions tested. Below 36, risk increases as the number drops, with readings under 24
typically flagging a surface as high risk, particularly when wet.

The short why
The PTV threshold exists because slip risk sits on a scale, not a pass or fail line. A floor
doesn’t become “safe” the moment it crosses 36, and it doesn’t become “dangerous” the
moment it drops below. The number tells you where a specific surface sits, under specific
conditions, at a specific point in time.

What the number actually means
A PTV is a measure of friction between a simulated heel strike and the floor surface. The
higher the number, the more grip the surface provides, and the lower the likelihood of a slip.
Readings are always tied to conditions: wet or dry, footwear assumption, and which zone of
the floor was tested.

This matters because the same floor can produce very different readings depending on where
and how it’s tested. A dry corridor and a wet poolside surround are not the same test, even if
they’re the same material.

Why a single “safe” reading isn’t the end of the story
This is the belief worth challenging directly. Many venues treat a PTV of 36+ as a box ticked,
filed away and forgotten. But a safe reading today doesn’t guarantee a safe reading next year.
Cleaning products, footfall, and general wear all shift a floor’s PTV over time, often without
any visible change to the surface.

Treating one good result as permanent proof is where risk quietly creeps back in. The more useful approach is to keep measuring, so a drop below the safe threshold is caught early rather than discovered after an incident.

What pushes a floor below a safe PTV
A handful of factors are usually behind a declining score:

• Contamination: grease, water or food debris sitting on the surface during testing or
  daily use
• Maintenance: cleaning products or methods that leave a residue, which can lower grip
  even on a well-specified floor
• Wear: gradual smoothing of the floor material under repeated footfall, particularly in
  high-traffic zones
• Environment: transition points between wet and dry areas, where readings often differ
  sharply from the rest of the room.

Any one of these can pull a previously safe floor below 36, without the change being visible
to the eye.

Why this matters for a hospitality or leisure venue specifically
Entrances, bars, kitchens and poolside areas are exactly where PTV scores are most likely to
move over time, because they combine high footfall with frequent contamination. A reading
taken at fit-out tells you nothing about how that same zone performs now. Slip Safety
Services has found that where organisations move from a one-off test to ongoing
measurement and improvement, they see a 57%+ average reduction in slip incidents. The safe
number only holds its value when someone keeps checking it.

What to do about it
Check when each high-risk zone in your venue was last tested, and what the PTV reading
was, wet and dry. If any zone hasn’t been tested in the last year or two, or was only ever
tested once at installation, treat that as a gap to close rather than an assumption to rely on.

Next step
If you’re not sure where your venue’s floors currently stand against a safe PTV, the Slip Risk
Scorecard is a quick way to see where the gaps likely are, before committing to a full
assessment.

Related questions
What is the pendulum test and how does it work?
How often should floors be pendulum tested to stay above a safe PTV?
Can cleaning products lower a floor’s PTV score?
What’s the difference between a slip test and a full slip risk assessment?

Check these out;
“Check your venue’s PTV risk with the Scorecard”
“The full method behind measure, improve, prove“