Thanks to Manda Ferguson, cosmetic chemist.
There are 16 main sensitisers in essential oils that if not calculated properly can cause a lot of damage. Each essential oil can contain only a few or quite a lot of each. Each sensitiser has its own amount that can be used and then on top the total of each sensitiser has a topical dermal limit for leave on and wash off categories which then also falls under 9 main and more sub categories on which way they are applied and to which area of the body.
Never attempt to use essential oils yourself for topical use or to ingest.
Essential oils with diffusion are different, but don’t have it running constantly.
Essential oils that can cause lung complaints in children under 12, so never have these around kids especially babies.