Short answer, yes. But only if they’re both platinum-cure silicone

Long answer:

Platinum Cure Silicone

Platinum-cure silicone is the industry standard for insertable toys. It’s the most stable over time and is the least likely to degrade over time. It is generally higher quality and more expensive. For medical and food purposes, platinum-cure is what is used. The alternative, tin-cure silicone, is used for molds or casting—not the end product. Tin-cure has a lifespan measured in months as opposed to decades.

This “good” silicone is inert and non-reactive. For insertable toys, this is perfect! This also means it won’t react with itself.

Other Materials

Other sex toy materials like jelly, PVC, and TPE are considered less safe because they’re porous or reactive. Jelly is not a good material as it can “sweat out” the plasticizers used to make it flexible. TPE is very porous and can absorb almost any substance it’s in contact with. If you were to store these types of toys together, then yes, you’re going to have a problem.

Before I learned about safer materials, I had some jelly and TPE toys that got mold. I didn’t know at first what it was, so I tried to wash them with soap and water, but nothing! The dark spots just wouldn’t go away. I had to discard the entire thing. Then shortly afterwards, I had a different toy get some blue coloring on it. It looked like something blue leeched onto it.

Hygiene

Never store toys dirty. Once you’re done use them, wash them right away. Soap and water is best and the most hygienic, then air dry. If you use a condom over it to make clean-up easier, then make sure they’re non-lubricated condoms and that they don’t leave any residue on the toy.

TL;DR: Storing Together

Silicone toys are expensive. I have a ton of toys that I toss in some big box, and they’re fine. But I understand not wanting to risk it. After all, high quality toys are expensive, and you don’t want to risk any damage. As silicone is a rubber, if you put something near it that’s leachable, it can take up that chemical. If it’s near some unsafe jelly toy? Yes, it can absorb those chemicals into itself. For best results, just store them in their own bags or keep them separate. 

Just as you wouldn’t store glass or metal toys together due to the risk of breakage or scratching, it’s best to give your silicone toys their own space to ensure they remain in good condition.