Using mortar trough as plant containers?

The mortar trough from the hardware store are typically cheaper than plant pots and seem more robust.

However it seems to me that they have are rubbery/plastic chemical smell to them.

Do you know whether they can be safely used for growing food?

As i didn't get an answer, here is a picture of the thing i have in mind:

I use these troughs for planting, have so for years.

Here in Germany, they are the cheapest alternative to big pots. To be honest, I am not sure on the aspect of possible leakage of the material. However, it can't be really dangerous as many people use them and show pictures and I hear no warnings, as in the case of wooden sleepers which were used some decades ago but which are not used anymore due to the dangerous coating they have.

I will keep my eyes open and post here if I find something definitive.