I don't discourage anyone from reading the ingredient list, but that is only the beginning of understanding. Every massage product, whether it be olive oil or a lotion with a dozen ingredients listed, is "full of chemicals." For example, we kid ourselves if we think "olive oil" is less "full of chemicals" than a bottle of lotion with a dozen ingredients listed. "Olive oil" is a simply a two word shorthand for literally hundreds of chemicals, including many chemicals known to cause cancer. Therefore, it's not surprising that some people are very sensitive to olive oil, and there are a number of massage therapists who cannot use it for that reason.
To look at another "natural" ingredient, based on your February 22 post, let's look at sodium hydroxymethylglycinate. Member Blisss listed this ingredient as, "Derived from glycine, which is a naturally occurring amino acid. Used as a preservative. No adverse effects." However, according to to US patent 4,337,269, its synthesis is from a solution of glycine, sodium hydroxide and formaldehyde. And in aqueous solution, sodium hydroxymethylglycinate decomposes to sodium glycinate and formaldehyde. Experimental data demonstrate that sodium hydroxymethylglycinate is a potential allergen, and exposure to formaldehyde solutions can cause irritation of the skin and allergic contact dermatitis. Exposure to formaldehyde vapor can provoke skin reactions in sensitized individuals even when airborne concentrations of formaldehyde are well below 1 ppm. Long term exposure to formaldehyde has been shown to be associated with an increased risk of cancer of the nose and accessory sinuses, nasopharyngeal and oropharyngeal cancer, and lung cancer in humans.
Does that mean it's unsafe to use a product containing a formaldehyde releaser like sodium hydroxymethylglycinate? According to the National Institute of Environmental Health Sciences / National Institutes of Health, formaldehyde is also a naturally synthesized product within the human body as a natural metabolite of methanol. The human body therefore has a built-in mechanism to metabolize formaldehyde, and this metabolic pathway must be overwhelmed before adverse affects are observed. However, because each person reacts differently, it is hard to say at exactly what level of exposure adverse affects begin to occur.
It would be nice if safety could be established simply by reading an ingredient list. But just as olive oil is "full of chemicals", safety isn't so simple.