Meth brainteaser – the parameters of ‘limited use areas’


The new meth standards that were released in June were welcomed by the meth testing and decontamination industry, as well as homeowners and those affected by potentially harmful properties.

One of the most interesting things about the standards was the introduction of two levels of methamphetamine contamination. A new contamination level was set at 1.5µg/100cm² for ‘high use’ areas, while the contamination level for ‘limited use’ areas was higher at 3.8µg/100cm², recognising that these places were accessed far less frequently and generally only by adults.

Since the standards were released there’s been much discussion about how you define each area and what part of the property comes under which label? The standards themselves give a brief definition of these terms:

High use area
An area in a property that can be easily accessed and is regularly used by adults and children.

Limited use area
An area that is likely to be accessed only by adults and for short periods of time. This includes crawl spaces and wall cavities not used as duct runs that are unlikely to be renovated.

Although a couple of examples were given within these definitions, there are many other spots in and around a home that now lie in a grey space.

What can we confidently say is a high use area?
From the definition itself in the standards, we can assume that any area that children could access will be a high use area. Given the spaces that kids can squeeze into, we can assume that almost the whole house or building will be a limited use area, including an internal or external garages or basements.

What’s in the murky zone for a high use area?

  • Sealed off crawl space in a basement easily accessible by smaller people – although if this was locked, would this change its definition?
  • What about crawl space or places that are always kept locked?
  • What about roof cavities that can only be accessed by ladder, where no ladder is present?
  • Pool equipment cabin?
  • Chimneys in the house?
  • Turrets?
  • A hidden bar behind a bookcase?
  • Locked underfloor trapdoors
  • Boat house or workshop?

With the standards so new, the industry is still waiting to see just how these definitions will be applied in actual cases, so until these are tried and tested, we need to make some assumptions now as since the standards were launched, we’ve had numerous queries about these spaces. Our approach is to err on the side of caution and also point out to you the places in your property that could fit into both definitions until confirmed otherwise.