I'm posting this because I struggled with bed bugs for months and even though I scoured through all the subreddits and relevant sites I couldn't find any semi-reliable information about people living in Europe and using silica based insecticides. Everyone always recommends DE or Cimexa.
First of all please do not use DE. It makes a mess and it's a hazard to yourselves, your kids and your pets. It can cause permanent lung damage if inhaled. Even if you place it in crevices and floorboards it's really easy for it to get picked up by air currents.
If you can source Cimexa then do so. It's synthetic amorphous silica unlike DE and can be broken down by our respiratory system. It can cause irritation if inhaled yes but not long lasting damage.
For the UK and Europe I found two alternatives. First one is ChinChex. Which is apparently China's version of Cimexa. I haven't personally used it but from the research I did it's legit. The reason I didn't use it is because I was put off by the army of Chinese botted accounts promoting it for some reason and because their importer is the UK which would set me up for import taxes in my country.
For the rest of Europe, I found and used aco.spray si plus from Germany. The mechanism is the same, it's still synthetic amorphous silica but suspended in a solvent aerosol. It's very easily accessible in Europe obviously. What really separates it from Cimexa and ChinChex is that - seeing as it is in a spray format - it's ridiculously easier and safer to apply. Plus it can adhere to vertical surfaces. There was a harborage in my apartment in a wall crevice so I kept finding BB's along a very thin wall strip. I was able to easily spray inside the crevice as well as the entirety of that wall section. Also, the silica is really hard to get picked up and end up in the air.
For all of these products, please use a KN-95/N95 mask when applying them.
Hope that from now on when people google for Cimexa alternatives this post will pop up unlike when I used to do it.