No, it is not an early April Fool's joke,Canon has really issued a recall for approximately 14,000 of its SX50 superzoom cameras for allergic reactions caused by the rubberized viewfinder. The problem: a chemical created in the vulcanization of the rubber used on the camera may cause the rubber around the viewfinder to change color and some people to experience an allergic reaction.
So, is there any reason to worry? Short answer: no.
The offending chemical, be Zinc N-N-dimethyldithiocarbamate, is a compound that is sometimes used as a bactericide, disinfectant, fungicide, and insecticide. The compound itself is not in the camera itself, but develops during the vulcanization of the rubber used for the viewfinder. As for what could happen, the camera's viewfinder could develop white stains if there is excess chemical present and, in some people with especially sensitive skin, allergic reactions could result.
Now for the good news: Canon has only received 3 reports of allergic reactions to the camera.
Want to know if your camera could have the bad viewfinder? According to Canon, the cameras impacted by the problem start with numbers 69-71 and have a '1' as the sixth digit in the serial number, located on the bottom of the camera. Anyone with one of the potential problem cameras is being asked to contact Canon in order to inquire about a fix.
For more info:
The Imaging Resource