Hello, I am not knowledgeable about chemistry whatsoever, but I run a company preserving bouquets out of my home and I have some questions about the silica that I use to dry flowers.
I use a brand called Activa silica gel which has a fine grain sand texture. I pour the silica over flowers in order to absorb the moisture out, and then pour it off of the flowers and bake the silica in the oven again to dry out, or reactivate the silica.
It's well known that flowers can have up to a dozen different pesticides by the time they make it to the shelf. I currently work with a face mask because it kind of freaks me out to breath in the silica dust that gets kicks up with a lot of use and probably stores some of the pesticides.
Essentially, though, I'm concerned that the silica is absorbing pesticides from the flowers and potentially causing harm both to myself and my roommate while it's heated in the oven.
The silica itself is labeled as non-toxic, but the product advises you not to reuse any of the plastic containers in which you've used the silica because the pesticides in the flowers can absorb permanently into the plastic and cause harm.
Could this same principle apply to my oven, or can anyone offer any insight into how pesticides might react under this kind of heat (250F for 4-5hrs)? Is a kind of gaseous effect possible for the pesticides when the silica is kicked up as dust or when evaporating with the moisture in the silica? Could the pesticides absorb into the oven and hang out there permanently? Any idea on the science behind whether it would help for me to regularly manually clean the oven or use the self-clean option using much higher temperatures?
I'm absolutely not asking for medical advice, and maybe this isn't even the forum to ask this kind of question, but any input is so so appreciated! My roommate and I both have health issues so I am really trying to take every opportunity I can to learn more about how these things work and maintain a ~nontoxic~ space. Thank you.