Mr. Clemens Kaiser
President and CEO
31220 Oak Creek Drive
Wixom, MI 48393
Dear Mr. Kaiser:
This responds to your request for an interpretation of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, Glazing Materials. You ask us whether the Exatec 900, a "coated plastic glazing material", may be used in vehicle areas specified for Item 2 glazing (safety glazing material for use anywhere in a motor vehicle except windshields) if it meets the prescribed groups of tests in the standard. The answer to your question is yes.
FMVSS No. 205 specifies at S5.1:"Glazing materials for use in motor vehicles must conform to ANSI/SAE Z26.1-1996 unless this standard provides otherwise".ANSI Z26 specifies performance requirements for various types of glazing (called "Items"), and specifies the locations in vehicles in which each item of glazing may be used. Section 4 of ANSI Z26 states: "The groups of tests listed in this subsection and shown in Table 1, item by item, are deemed adequate for determining the locations in the motor vehicle for which the various safety glazing materials that qualify under this standard may be suitable."The section further states: "Safety glazing materials in motor vehicles shall comply with the applicable requirements listed in this subsection and shown in Table 1, item by item, in definite groupings of tests that are appropriate for the safety glazing material in question, and the location in the motor vehicle in which it is intended to be used. (Emphasis added. )
For Item 2 glazing, Table 1 specifies the following safety glazing materials: laminated glass, tempered glass, class 1 multiple glazed unit and class 2 multiple glazed unit. However, in the "Note:" at the bottom of Table 1, the following is stated:
For convenience, each column on this table (as well as the text of the tests that follow) designates the specific type of material that will meet the enumerated tests if it is of satisfactory quality. If and when other materials are developed that possess properties so that they also meet one or another of the prescribed groups of tests, they may be used interchangeably with the corresponding materials specified in this table. (Emphasis added.)
The second sentence in the "Note:" to Table 1 permits Exatecs certifying the Exatec 900 as AS-2. It provides that if another material such as plastic glazing can be shown to "meet one or another of the prescribed groups of tests," the plastic glazing may be used interchangeably with the corresponding materials (i.e. , laminated glass) specified in Table 1.
We note, however, there are issues--including weathering, chemical resistance, and flammability--particular to the use of a "coated plastic glazing material" such as the Exatec 900 that are not addressed in the grouping of tests for the certification of AS-2 glazing. Thus, the second sentence in the "Note:" to Table 1 results in removing the consideration of weathering for plastics being used for the first time in locations critical to visibility as substitutes for laminated glass. This is a concern because the loss of visibility due to haze caused by weathering is a typical failure mode of polycarbonate plastics under exposure to sunlight that does not occur at all in glass glazing.
However, we also note that Exatec 900 is an advanced glazing material consisting of a core layer of polycarbonate which is surrounded by multiple layers of plasma deposited materials designed specifically to provide protection from the effects of solar radiation. Exatec states that the advanced technology incorporated into its Exatec 900 material provides significant weathering resistance protection that results in a useful life span of at least 10 years. The weathering resistance of EXATEC 900 has been independently evaluated by Batelle Laboratories of Columbus, Ohio. Batelle concurred with Exatecs predicted life span for its glazing material.
We plan to undertake rulemaking to propose additional tests for polycarbonate glazing. We request that Exatec provide details for its accelerated aging test methodology for public comment in the rulemaking proceeding.
Stephen P. Wood
Acting Chief Counsel