"It is, which is pretty safe on the train." Senku gestured between them. "I'm curious about something. I want to trade them." He explained.

"Then I want to get some urushiol which I am very allergic to, and put both of our hands near the open container to see if my SCA on your arm beeps, or if yours adapts temporarily to my allergies."

Senku paused. "It probably wouldn't be more than a few minutes, so I can't think of any long term effects and I promise not to touch it. I don't need to, my SCA usually warns me ahead of time."