No, is the short answer. Although they may be safe for some general uses, scotch brite pads should not be used on any surface where safe removal of oxidation or corrosion is undesirable - such as headlights that have become dulled due to oxidation or weathering conditions.
For such surfaces, it is possible that the combination of oxidation and/or weathering and harsh scouring can result in irreparable damage to the surface.
Why shouldn't Scotch Brite be used on headlights?
The reason has to do with something called surface texture. The front of your car is designed to create low pressure area on top of the windshield. This causes an updraft that helps pull dust and moisture off the window, making it easier to see through.
It also propels rain away from the glass, helping make it easier to see in wet conditions. That's why auto technicians tend to be pretty tight-lipped about letting customers or mechanics apply anything abrasive like scotch brite that might scratch up that delicate plastic film over the headlights.
Why is keeping headlights intact so important?
Keeping headlights intact is important for a safety reason. Headlights make it much safer to drive at night by increasing the field of vision, especially when there are no street lights. Headlights help the driver see what he or she needs to on the road ahead and decrease the possibility of accidents occurring from low visibility.
In areas where there are large agricultural facilities, keeping the headlights intact also helps drivers avoid hitting animals that wander onto roadways unexpectedly due to darkness. If a headlight is broken, you should have your car towed to an auto shop so that an automotive technician can replace it properly and without incident. Replacing a broken headlight is not a difficult task for a trained mechanic because they will already have all necessary replacement parts in stock.