If giving vinyl scraps to schools be sure to advise the teachers that the material may contain phthalates in concentrations higher than US federal standards allow for use by children (other countries may have similar restrictions). Phthalate compounds are substances now banned in most items for use by children under 12.
Additionally, when in scrap form small children may chew on it, and it's a serious choking hazard. If swallowed it will block the airway and could cause suffocation. Sadly, there are known instances of this occurring. Teachers can use it to make finished projects, if the projects are out of the reach of children, but it should never be directly used by children.
Oracal makes a point of the DEHP concentrations in their safety sheets for 631, 651, and many other of their products.