Interpretation ID: nht92-9.17

DATE: February 8, 1992

FROM: Carl C. Clark -- Safety Systems Company

TO: Paul Jackson Rich (Rice) -- Chief Counsel, NHTSA

TITLE: CC-92028

ATTACHMT: Attached to letter dated 4/9/92 from Paul J. Rice to Carl C. Clark (A39; Std. 205)

TEXT:

I would appreciate your legal interpretation of the glass-plastic glazing types covered by the designation AS-14 in Federal Motor Vehicle Safety Standard 205. The definition reads,

" 'Glass-plastic glazing material, means a laminate of one or more layers of glass and one or more layers of plastic in which a plastic surface of the glazing faces inward when the glazing is installed in a vehicle."

Subsequently in the standard, Item AS-14 Glass-Plastics are identified as glass-plastic glazing materials that pass certain tests and meet labeling requirements. These may be used anywhere in any motor vehicle except a convertible (a restriction added because of the possible degradation of the plastic layer(s) by direct sunlight).

This prohibition of the use in convertibles of AS-14 glass-plastic glazing, and AS-15A, Annealed Glass-Plastic Glazing, was subsequently limited to the windshield, allowing the use of these materials for the side and rear windows of convertibles (57 FR 1652, January 15, 1992). Item AS-14 has no stipulations as to the nature of the glass other than those qualities examined by the stipulated tests, and indicated by the required label. Is this a correct interpretation?

In response to a General Motors Corporation letter/petition (56 FR 12669, March 27, 1991), clamping of the glass-plastic glazing sample was allowed for Test 26, (effective date September 26, 1991, revised by the correction - 56 FR 49149, September 27, 1991, to be "effective upon publication in the Federal Register"). With clamping, a test of penetration through the material could be achieved for a two-ply glass-plastic glazing sample. Without clamping, the sample might crack and fall through the test frame without demonstrating its penetration resistance.

My understanding, then, is that if one meets the requirements of AS-14 material, whatever the form of the "glass," one can today use this material for automobile glazing in any position, except for the windshield of a convertible. Please correct me if I am wrong. This would therefore include a "tempered" or an "annealed" glass-plastic glazing, even though one could also call the "annealed" glass-plastic glazing used for a side window "Item 15A" (56 FR 18526, April 23, 1991). A Supplemental Notice of Proposed Rulemaking (56 FR 18559, April 23, 1991) has proposed calling "tempered" glass-plastic glazing Item 15B, to be used anywhere in the motor vehicle, excluding the windshield. The final rule on this proposal has not yet been issued.

May I note my understanding that the tempered glass-plastic side window material developed by DuPont and used in the contract for which I was the Contracting Officer's Technical Representative while at NHTSA (NHTSA Report DOT ES 807 397, Contract DTNH22-87-c-07442) and in my research reports with Peter Sursi (SAE 851203, 870320, and 890226) would pass all of the AS-14 requirements, once clamping is allowed for Test 26, and so could be designated as AS-14 material, with proper labeling, and put into use immediately. Please correct me if I am wrong.

May I note that the terms "annealed" and "tempered" are qualitative terms for a quantitative process of heat treatment of the glass as if cools from the melted condition. In the discussion of the new glass-plastic "items" 15A and 16A and 16B (56 FR 12669, March 27, 1991), NHTSA agreed to drop the "proposal to prohibit the installation of strengthened glass-plastic glazing in windshields and other locations requisite for driving visibility." This was because of industry comments that the term "strengthened" glass is, in effect, another qualitative term for the quantitative process of heat treatment, intended or a consequence of the industrial process used. Even annealed glass is "strengthened" to some extend, and windshield edges are appropriately tempered to some extend to reduce breakage in installation. A potential future difficulty with Items 15A and 15B is the need for a quantitative definition of conditions and proportion of the total surface that leads to or defines when a glass is "annealed" and when "tempered." To what extent can the small test sample be considered representative of the entire glazing piece used in the vehicle? In my view, the problem disappears if the glass, however named, meets the tests specified for AS-14 material, in which case it can be labeled AS-14, with the appropriate warning label also added as required, and put into general use immediately. Please correct me if I am wrong.

A number of companies have been running road tests of two-ply tempered glass-plastic side windows. My hope (and plan) is to have more of these tests, a process that can extend beyond private use, in my view, if indeed the glazing meets AS-14 requirements. May future road tests go forward with commercial installation of after-market glass-plastic glazing that meets the AS-14 tests and is properly labeled, whatever the designation of the glass component?