Here are some more strange warnings on items.

On a packet of juggling balls:
"This product contains small granules under 3 millimeters.  Not suitable for children under the age of 14 years in Europe or 8 years in the USA."

Seen on a camera:
"This camera only works when there is film inside."

On a bottle of flavored milk drink:
"After opening, keep upright."

On a can of windscreen de-icing spray:
"Spray works in sub-zero temperatures."

On a can of insect spray:
"Kills all kinds of insects!  Warning: this spray is harmful to bees."

A different brand of insect spray:
"Kills flies, wasps, mosquitoes, midges, and other flying insects.
Not tested on animals."

On an ocean buoy for determining the position of submarines:
"Protect from seawater."