I have a theory on why some people say pine is not a problem and why others have problems with using pine Substrate.
Now I do some aromatherapy.. And the correct way to study a plant is going by the Botanical Classification (Pinaceae) or (Pinus) latin names... Covers most Pine and some cedar type pine.
There are a large selection of pine trees out there. Why some people say they have no problems with pine substrate and other's will.
For pine in EO's scotch and Long leaf can cause problems for humans. But most essential oils being use is always with a carrier oil. EO"S are not directly used on the skin.
Now Pine can contain some terpentines. Depending once again on the botanical classification.
Dwarf Pine however is safe for humans and has Analgeic, antimicrobial, antiseptic quailties. This family includes Mungo, Montana, Pumilio, Mountain Swiss.
But for those using it, I would suggest looking up and see what type of pine you use, for your corns and if you have not had problems the its the type of pine substrate you are using.
Find out the botanical classification for it. Also always check 3 different sources when looking for a Botanical classification
I know looking at Home Depot's section of Pine Mulch I would not buy anything that says it has a natural insect repellent in it. I saw plenty of those looking for cypress mulch yesterday for my Rough Green.
Also food for thought.. You can call the company directly for the product you are using and ask
They have to give you list of ingredients the main being most to the last being less.