KiwiRail’s health, safety and environment department
Zero porosity
The ratio of the open area to the closed area in fabric. Graded as high, low or zero, porosity indicates the ability of the canopy material to allow air to pass through it. Zero-porosity fabric is treated to obtain that grade
Zero-porosity
This indicates the fabric’s ability to allow air to pass through it. Porosity is the ratio of the open area to the closed area in fabric. Graded as high, low or zero, porosity indicates the ability of the canopy material to allow air to pass through it. Zero-porosity fabric is treated to obtain that grade.
