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.
- polyvinyl acetate (PVA), used in paints and adhesives, such as white glue, and. - polyvinyl butyral (PVB), used in safety glass films. What differentiates PVC from the other vinyls is the addition of a chlorine molecule (the. chloride âCâ in PVC and PVDC). Chlorine is the source of many of the environmental health. concerns with PVC, such as the generation of dioxin, a highly carcinogenic chemical produced in.