23 Manufacture of non-metallic mineral products
- 231 Manufacture of glass and glass products
- 232 Manufacture of refractory products
- 233 Manufacture of ceramic and clay building materials
- 234 Manufacture of porcelain and ceramic products
- 235 Manufacture of cement, lime and plaster
- 236 Manufacture of concrete, plaster and cement
- 237 Cutting, shaping and finishing of stone
- 239 Manufacture of other abrasive products and non-metallic mineral products n.e.c.