Here is the symbol used in the US for food that has been irradiated the process called radurization. I'm not sure how common it is and I've never looked for the symbol. I do recall years ago how people were upset about "radioactive food" due to irradiation. It's done using gamma rays or x-rays not particles.
Many if not most modern plant cultivars had at some point irradiation used on them to increase mutation rates to find interesting mutations with higher yield, higher resistance etc.
This has worked especially well in rice, chances are between 5% and 25% depending on country you're eating rice from a cultivar that has been bred using radiation.
That's done in these cool-looking atomic gardens where you have a radiation source in the middle and then plants are seeded in circles around it. The inner-most circle dies, the outer-most circle stays the same, the middle is interesting to breeders, you can see those on google earth, there's a picture here: https://99percentinvisible.org/episode/atom-garden-eden/
It's one of the things the consumer would be very upset about if told, but has been living fine with for decades, like the fact that your insulin, your washing powder, and your contact sense solution is made by genetically modified bacteria.
Yep, this is funny - people have problem with GMO where we have atleasts some idea what the modification did but at the same time most of what people eat was created by radiation induced random mutation.
The color green, the imagery of leaves. This symbol clearly invokes the natural and warm feelings commonly associated with blasting things with nuclear radiation.
https://en.wikipedia.org/wiki/Radura