8X ND filter: UV warning

I just received a Hoya HMC 8X ND filter.
In the box is a circular insert that says:
UV Alert
large !... UVA: 320nm - 380nm
two large !!... UVB: 280nm - 320nm

That's all it says. What's the alert?
Does it =not= block those wavelengths? Does it block them more than
usual?
What is the significance?
TIA

 

Yes, UV Light pass through the filter, you can see spectral transmission
diagramms for many hoya ND filters at:
http://www.hoyaoptics.com/color_filter/neutral_density.htm

This means: Don`t use the filters with long lens an look through your
camera to the sun, it may visual looks good, but cause the UV pass full
through the filter your eys will hurt. Probably your camera get´s damaged
too.

Eventually your eys will even hurt, if you use it without lens to look at
the sun: Your eys get less illumination --> get wide open. And the UV paas
throuh an burn your retina.

Markus

 

Thanks a lot for the info Markus.

 

It's probably the standard not-very-well-worded warning for those who
might use one of these to look at the sun, particularly during a solar
eclipse.

 

I believe the lens of the eye is most affected by UV with cataracts
resulting. There may be retinal damage too.

 

I would imagine it means that if you plan to look at the sun with this
filter attached that you should be warned against it, as it could
cause eye damage.

 

The little circle path is a light sensitive material. If you have that exposed to the sun it will turn blue.

If you have a UV filter on top, it will remain the same color as long as the filter is effectively reducing the UV light.

IT IS NOT JUST A WARNING SIGN! It is a piece of special paper that let you test out the filters