On Food Contact: 

Scientific studies that were conducted to understand the exposure to kitchen towels and napkins show that exposure is very low. This result convinced the Council of Europe that the use of kitchen towels and napkins does not pose a risk to the health of consumers.

• Exposure and migration of food to tissue – IPSOS

• Recycled fibres & fluorescent whitening agents – PIRA Int’l  (n.a.)

• Tissue specific Migration test – Council of Europe  (n.a.)

There are some significant differences between the level of exposure and associated requirements for Tissue Product and for Packaging Materials for Food conservation.
In any case, to allow a more complete picture, here and in the box on the right there is a link to the CEPI Industry guideline for the Compliance of Paper & Board Materials and Articles for Food, which applies to Packaging Materials.