DH certainly seems to think so! Older two DC off to sports day 'camp' tomorrow and Tuesday. They usually have school dinners so we don't have lunch boxes for them and I totally forgot they'd need packed lunches until yesterday. We don't have many shops near us so the only thing I could get at such short notice was a couple of those Sistema 'clip and lock' plastic boxes, which I think will be fine. Plus they have the added bonus of being useful for picnics/food storage!
DH thinks I am being totally U and the DCs will never forgive me for not buying them stupidly expensive 'proper' lunchboxes. Oh and that everyone will laugh at them for taking their lunches in plastic boxes. Who is BU here MN jury?