However, there is no consensus among volcanologists on how to define an active volcano. As of 2012, PHIVOLCS lists 23 volcanoes as active in the Philippines, 21 of which have historical eruptions; one, Cabalian, which is strongly fumarolic volcano [further explanation needed]; and one, Leonard Kniaseff, which was active 1,800 years ago (C14).
Polyvinyl Chloride PVC. Polyvinyl Chloride (PVC) is a major plastics material which finds widespread use in building, transport, packaging, electrical/electronic and healthcare applications.
Rigid polyvinyl chloride conduit (PVC) is a rigid nonmetallic conduit that provides many of the advantages of RMC, while allowing installation in areas that are wet or corrosive. PVC conduit is an inexpensive, easily installed raceway.