Basically assume allergians can be in anything and check the lables of EVERYTHING!
Read labels and call the company. I read labels 3x - once at the store, once as I am putting things away, and once more before I cook with the product.
Maple Syrup- uses a de-foaming process so it doesn't boil over the sap. An oil of some kind is often used: soy and dairy (butter) are the most common. Some companies use canola or safflower oils. It is a veeery small amount that is used and basically tiny trace amounts that are left but with a severe allergy, it is better to know and be safe rather than sorry!
Not all olive oils are created equal, actually not all olive oil is actually even pure olive oil but is cut with other oils (soy). We use Kirkland's organic extra virgin olive oil. I have heard good things about California Ranch brand too.
Not all canned pumpkin is actually pumpkin.
Britta filters use a coconut product to help filter.
A lot of bottled water is "corny".
Art supplies... they are chalk full of allergens! Such as (but not limited to!) dairy being in chalk, gluten/wheat products in glue, soy in crayons, markers, and paints. Discount School Supply is a company we like as they are very helpful at sharing allergens in their products. The Colorations brand is especially good at this.
For the older allergy individual - condoms can contain dairy in the lube... not a time when you want to have an allergy attack!