HIRM is an acronym for heat island reduction material. HIRM A is a special coating developed by Kansai Paint to keep down the rise in the surface temperature of asphalt or concrete under the summer sun. Materials like concrete absorb the heat in the sun’s infrared rays, giving rise to the heat island phenomenon. HIRM A contains a pigment to reflect these infrared rays and inhibit heat conduction so that concrete does not take on heat.