Document ID: chunk:federal_register_of_legislation:F2015C00542:front:0:p6
Version: federal_register_of_legislation:F2015C00542
Segment Type: other
Provision Reference: 
Character Range: 18448–21353

of two or more layers of glass held together by one or more interlayer of plastics material; it may be:
2.2.1. "Ordinary laminated glass", when none of the layers of glass of which it is composed has been treated; or
2.2.2. "Treated laminated glass", when at least one of the layers of glass, of which it is composed, has been specially treated to increase its mechanical strength and to condition its fragmentation after shattering;
2.3. "Interlayer" means any material designed to be used to hold together the component layers of laminated-glass.
2.4. "Safety-glass faced with plastics material" means glazing as defined in paragraphs 2.1. or 2.2. with a layer of plastics material on its inner face.
2.5. "Glass-plastics" means glazing consisting of any glazing material that comprises one layer of glass and one or more layers of plastic in which a plastic surface of the product faces the inner side.
2.6. "Plastic glazing" is a glazing material that contains as an essential ingredient one or more organic polymeric substances of large molecular weight, is solid in its finished state and, at some stage in its manufacture of processing into finished articles, can be shaped by flow.
2.6.1. "Rigid plastic glazing" means a plastic glazing material which does not deflect vertically more than 50 mm in the flexibility test (Annex 3, paragraph 12.).
2.6.2. "Flexible plastic glazing" means a plastic glazing material which deflects vertically more than 50 mm in the flexibility test (Annex 3, paragraph 12.).
2.7. "Double window" means an assembly of two panes separately installed within the same opening of the vehicle.
              2.8. "Multiple-glazed unit" means an assembly of at least two parallel panes permanently assembled in manufacture and separated by one or more gap(s).

              2.8.1. "Symmetrical multiple-glazed unit" means a multiple-glazed unit where all component panes are identical (e.g. all uniform toughened glass).

2.8.2. "Asymmetrical multiple-glazed unit" means a multiple-glazed unit other than a symmetrical multiple-glazed unit.
2.9. "Bullet resistant glazing" or "Bullet-proof glazing", means glazing constructed so as to be resistant to firearms.
2.10. "Principal characteristic" means a characteristic that appreciably modifies the optical and/or mechanical properties of a safety glazing material in a way not without significance to the function which it is intended to perform in a vehicle. The term also covers the trade names or marks as specified by the holder of the approval.
2.11. "Secondary characteristic" means a characteristic capable of modifying the optical and/or mechanical properties of a safety glazing material in a way which is of significance to the function which it is intended to perform in a vehicle. The extent of such modification is assessed in relation to the indices of difficulty.
2.12. The term "indices of difficulty" covers