Yes, the only way to know for sure about shared lines is to call the manufacturer.  It's also worth noting that many manufacturers have regional differences and/or facility codes that may be safe or unsafe.  The only way to know those things is to call.

Also, "safe" candies aren't always safe.  Often they are repackaged with unsafe candies or in an unsafe facility.

Please also note that labelling for "May contain" as to allergens and/or "Shared Facility" or "Shared Line" is

absolutely optional and that many companies DO NOT label for these situations, including possibly

some of the manufacturers and products included on that very list.

As moderator for this Schools board, and as a Committee Member for the FAS community,

I feel it is critical that the stated disclaimer from this source be posted here:

Quote
DISCLAIMER: ALL INFORMATION REGARDING INGREDIENTS AND
MANUFACTURING PROCEDURES WERE COMPILED FROM CLAIMS MADE BY
THE PRODUCTS' MANUFACTURERS ON THEIR LABELS AND MAY ALREADY BE
OUT OF DATE. ALTHOUGH EVERY EFFORT HAS BEEN MADE TO BE AS
ACCURATE AS POSSIBLE, PLEASE NOTE THAT WE DO NOT ACCEPT ANY
LIABILITY FOR ERRORS OR OMISSIONS MADE BY US OR THE PRODUCTS'
MANUFACTURERS. THIS LIST IS FOR INFORMATIONAL PURPOSES ONLY AND IS
INTENDED TO SERVE AS A GUIDE, NOT AS AN AUTHORITATIVE SOURCE. PRIOR
TO PURCHASING ANY RECOMMENDED FOOD ITEM, IT IS YOUR
RESPONSIBILITY TO CHECK THE INGREDIENT LIST TO ENSURE THAT UNDESIRED
ALLERGENS ARE NOT COMPONENTS OF THE INGREDIENTS OR THE
MANUFACTURING PROCESS.

You can find a long, frequently updated list of snacks that are peanut, tree nut, egg and sesame free at snacksafely.com. The schools, sports leagues and religious programs in our area use it as their "approved" snack list. It includes a disclaimer that warns parents/caregivers to *always* check the label before giving a snack to a food allergic child.