Sure- most any acoustic sealant type caulk would work, and an low-expansion sealing caulk like Backerseal fills the bill.

Toxicity of the isocyanates used in 1-part gun-foam are pretty low compared to others in that class, but those few people who have an allergic sensitivity to isocynates probably shouldn't be the persons doing the installation. The total quantity/exposure is pretty low post-installation, given the extremely low surface area involved- nowhere near the same lingering exposure as spraying 2" of 2lb foam as the insulating layer (which is also pretty low.) When used solely for seam sealing, even very modest ventilation rates I'd be a bit surprised if it would be detectable even with a gas spectrometer in an air sample 10 days post-installation.