Fragranced products are only the tip of the iceberg
"All natural," "organic," and "fragrance free," do not automatically mean "safe." Arsenic and cyanide are natural and organic. Radon and carbon monoxide are both "oderless." Every one of them will kill any human in sufficient dosage.
Recently, more and more attention is being focused on the fact that manufacturers don't need to disclose the ingredients which make up the "fragrance" entry on product lables. With "fragrance" going out of style, manufacturers are turning to nastier chemicals.
For instance, modern cat litter formulas use questionably safe chemicals. Some these days have no smell or odor but break down odor molecules in the air. Even trace amounts of these allegedly safe chemicals cause typical MCS reactions in those susceptable.