The body for a long time contact silicone O-ring and other silicone products will be affected?

Long time. Touch silicone silicone tube, O ring, O ring, silicone rubber products have effects on the body, so long time. Touch silicone silicone tube, O ring, rubber seals and other products to the body will have no effect, a few days ago, my friend said her husband working in the production of printer in the factory, he will often touch operation part of the silica gel, he said after class feeling a bit astringent pain dry eyes. The smell inside the factory is also a bit pungent, she asked me this is harmful to his health?
The first silica gel is non-toxic, but I found above the jhdlab safety performance information above to see the G of silica gel has a sentence: eye touch after: impact. Usually the substance as inert matter, will form a strong damage when attached to the eyes! What would touch many chemical reagents, more or less will be a little bad, so the best is to take some protective measures, such as professional protective glasses etc..