Originally posted by: Zenmervolt
They are _not_ "DOT Approved".
From a very reputable lighting consultant:
What about blue-tinted headlight bulbs that I found at a local auto parts store, or on the internet? They're sold as being "DOT Approved". Are these legal?
Probably not.
There's no such thing as "DOT approved". DOT does not "approve" products as the European regulatory body does. Rather, the manufacturer of an item of motor vehicle equipment is legally obligated to self-certify that his product complies with all applicable regulations. For some items of equipment, such as headlamp bulbs, the certification takes the form of a "DOT" marking on the bulb base. However, there is no legal obligation for the manufacturer to submit his product for government testing before applying the marking, and many companies go ahead and apply the marking even to bulbs that do not comply with the law. The relevant regulations (US Federal Motor Vehicle Safety Standard 108, Canadian Motor Vehicle Safety Standards 108 and 108.1, and ECE Regulations 8, 20, 37, 98, 99, 112 and 113 all call for "white" light, defined as discussed above, so the statement of DOT compliance itself is false for a bulb that emits a light color obviously different from "white".
http://www.danielsternlighting.com/tech/bulbs/blue/bad/bad.html
ZV