Page 247 - PortWest

WATERPROOF AND BREATHABILITY NUMBERS
WHAT DO THEY REALLY MEAN

FOR WORKERS?

MM
WATERPROOF

190T

3,000 - 10,000 MM 10,000 - 20,000 MM 20,000 MM +

The minimum rating for a garment Will withstand moderate to heavy Suitable for those working outdoors
to be called waterproof, suitable for rain but may soak through if in extreme weather conditions, wind
working in light to moderate rain. subjected to pressure such as and heavy rain.
kneeling in very wet conditions.

Waterproof ratings are measured in millimeters (mm), ranging from 800mm to
20,000mm. For example 10,000mm indicates that a fabric can withstand the pressure of a Waterproof Level
10 meter tall column of water pushing on it before it starts to let any water through.

MVP
BREATHABILITY

3,000 - 10,000 MVP 10,000-20,000 MVP 20,000 MVP +

Suitable for light physical Suitable for heavy physical Suitable for heavy physical
activity which causes minimal activity which results in signifi cant activity which results in signifi cant
perspiration. perspiration, will require rainwear perspiration, will require rainwear
this breathable. this breathable.

MVP is Moisture Vapor Permeability expressed as g/m²/24 hours, it is the number of
grams (g) of water vapor that can pass through a square meter (m²) of fabric from the Breathability Level
inside to the outside in 24 hours. The larger the number, the more breathable the fabric.

243