Seeing that you have your food hermetically sealed in bags anyway, health issues are not something I’d worry about. The Ikea box is made out of PP (polypropylene). That’s not terribly suitable for higher temperatures. Once you go over 60-65 ℃, the plastic goes a little soft. It’ll smell of plastic a little. Once you go towards the boiling point, the container may deform (although I wouldn’t expect it to melt outright).
I’d be inclined to give the Ikea box a miss and go with something more suitable, such as a polycarbonate container.
Michi.