After the toothpaste, here comes the pen with dangerous chemicals, but... with made in USA inks!
A purple color "UV Pen" or "Spy /detective pen " or "Invisible ink pen" manufactured in China allows youngs kids love they unlock secret hidden messages likes detective do, or hide their secrets in their notebook while nobody will be able to read their secrets.
Inside some of these (purple color) pens, the made-in-USA ink, manufactured by National Ink, Inc. (Santee, California) under reference SW (for "Secret Writer" Ink), used to be manufactured by the company using Ethylene Glycol Phenyl Esthers and Diethylene Glycol Mono Ethyl Esthers, which are very dangerous ingredients, especially for children related products.
Some children are using the pen to write words (such as love messages) directly on their face in order to flirt-with girls while dancing under the spotlights, threfore putting their skin in direct contact with the esthers.
Today, the US company changed the formula for a safer option, but some Chinese factories are still providing the old certificate, as if they had been able to source the dangerous (cheaper) ink from within China while showing the US company past certificate in their hands.
It seems that National Ink used to sell this ink for manufacturing the pens a long time ago before switching to a safe alternative, and that some chinese factories switched to a local hazardous esther preparation of their own to keep costs down, while others did accept to pay the new preparation from National Ink. Some price differences noticed in China in April 2008 for this product seem to go in this exact direction. We are still in doubt, but the question is on the table now.