Anyone with eczema needs to avoid Formaldhyde releasers; avoiding these in pregnancy a good idea.
Another big problem with preservatives is formaldehyde. Many of the preservatives kill bacteria and mold by becoming formaldehyde. Many countries will not all allow this because formaldehyde is a knonwn cancer risk.From Cancer.org (American Cancer Society):
“Exposure to formaldehyde has been shown to cause cancer in laboratory test animals. Exposure to relatively high amounts of formaldehyde in medical and occupational settings has been linked to some types of cancer in humans, but the effect of exposure to small amounts is less clear.”