Hand sanitizers are flammable.They show blue flames which can only be seen in dark.Please read more details below this image.
Warning on use of alcohol-based hand sanitizers by oil and gas
Don't Catch Fire When Using Hand Sanitizer, a Defense Safety
To help prevent the spread of novel coronavirus (COVID-19
Can Hand Sanitizer Spontaneously Combust? - Richmond Fire-Rescue
This is why methanol fires can be so dangerous. They are invisible
Prevent Hand Sanitizer Burns Office of Environment, Health & Safety
Color-Changing Invisible Ink
Antipespirant & Deodorant for Men Invisible Dry Spray, 122 g
UVC wands kill viruses. Experts warn they're also a 'major safety
FACT CHECK: Can hand sanitizer catch fire in your car?