I don't think you can make that generalisation. It's more about the nature of the compounds. Generally speaking, from a Western perspective at least, more modern munitions will be much less reactive than old ones, but the Insensitive Munitions classes don't really differentiate.
If as suggested the Toropets facility was reworking NK artillery shells, then I wouldn't be surprised if they met no IM standards at all.
If you have time, it's worth checking the definitions used for IM levels to get a sense for what they mean - it ranges from terrible (Hugh order detonation )to pretty unpleasant (burns vigorously without much propulsive effect), there's not really a "safe" category for real world systems.
(This from memory, so might be oversimplified or otherwise mildly inaccurate.)