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Interpretation ID: 2703y

Mr. W. Marshall Rickert
Motor Vehicle Administrator
Maryland Department of Transportation
6601 Ritchie Highway
Glen Burnie, MD 21062

Dear Mr. Rickert:

Thank you for your letter seeking this agency's opinion as to whether the State of Maryland may amend its motor vehicle regulations to permit the installation of aftermarket tinting on motor vehicle windows, for individuals who may desire this for medical reasons. I am pleased to have this opportunity to describe the legal principles that relate to your question.

The National Highway Traffic Safety Administration ("NHTSA") is responsible for issuing Federal motor vehicle safety standards that impose requirements for specific levels of safety performance for new motor vehicles and motor vehicle equipment. Federal Motor Vehicle Safety Standard No. 205, Glazing Materials (49 CFR 571.205), which has been in effect since 1968, imposes a minimum level of light transmittance of 70 percent in all areas requisite for driving visibility (which includes all windows on passenger cars). The purpose of this requirement is to ensure adequate visibility through the windows, thereby reducing the risk of a motor vehicle crash.

Although Federal motor vehicle safety standards apply directly only to new vehicles and equipment, Federal law also imposes limits on the addition of tinting materials to motor vehicle glazing after vehicles have been purchased by consumers. Pursuant to section 108(a)(2) of the National Traffic and Motor Vehicle Safety Act, 15 U.S.C. 1397(a)(2), manufacturers, distributors, dealers, or motor vehicle repair businesses may not "render inoperative" any equipment or element of design installed in compliance with a Federal safety standard. Thus, those businesses may not install tinting that reduces the light transmittance of windows covered by Standard 205 to a level below the Federal requirement of 70 percent, since that would make the windows "inoperative" within the meaning of Standard 205.

This Federal prohibition is similar to that imposed by section 22-104 of the Maryland Vehicle Law, which provides: A person may not willfully or intentionally remove or alter any safety device or equipment that has been placed on any motor vehicle . . . in compliance with any law, rule, regulation, or requirement of . . . the United States or of this State . . . unless the removal or alteration is permitted by rule or regulation adopted by the [Maryland Motor Vehicle] Administrator.

The "render inoperative" provision of Federal law does not apply to actions by individual vehicle owners. Therefore, each State may regulate the extent to which aftermarket tinting may be applied by vehicle owners to their own vehicles. Thus, although section 22-104 appears to preclude aftermarket tinting by any person if the result would be to reduce the level of light transmittance below 70 percent, Maryland may amend its rules or regulations to permit such tinting by individuals, for medical or any other reasons deemed valid by the State. However, Maryland has no authority to grant any exemptions, including medical exemptions, from the "render inoperative" prohibition of Federal law that applies to commercial entities. Hence, regardless of any provisions of Maryland law, no manufacturer, distributor, dealer, or motor vehicle repair business may legally install window tinting film on a vehicle, unless the vehicle continues to comply with the Federal light transmittance requirements.

In adopting Standard 205, NHTSA determined that a minimum light transmittance of 70 percent is necessary to meet the need for motor vehicle safety. This is the same level of light transmittance contained in the Safety Code of the American National Standards Institute. If, as your letter suggests, Maryland is considering permitting vehicle owners to modify their vehicles such that their windows will have a lower level of light transmittance, we would urge you to carefully consider the safety consequences of such an exemption.

Please let me know if you need any further information on this subject.

Sincerely,

Paul Jackson Rice Chief Counsel

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