Why paraben free? Why preservative free?
What are parabens? Parabens have been used to prevent mold growth in personal care products for decades. Methyl paraben was first discovered on fruits such as blueberries.
A recent study in England discovered parabens in breast cancer tissue. There is also concern that parabens may be an endocrine active chemical.
For further information Wikipedia has a good, unbiased discussion here.
These concerns have led careful consumers to seek out paraben free products.
What does preservative free mean? Products that contain no ingredients that are considered preservatives are preservative free. This does not mean that your lotion will go bad - natural ingredients that inhibit microbe growth but are not considered preservatives are included in the formula.
It is important to have some system to preserve lotions and shampoos to prevent the growth of potentially harmful molds and bacteria. Products that contain no water, such as oils, do not need preservation.
While no study has found approved preservatives to be harmful consumers have become concerned about potential harm from them.
Many natural ingredients have been discovered to inhibit microbe growth, from essential oils and natural perfumes to moisturizers derived from coconut oil.