Okal house from 1979 formaldehyde exposure?

Good morning everyone,

my girlfriend and I are currently in the process of buying a prefabricated Okal house from 1979.
The asbestos used has already been professionally removed by a company.
Now the question arises about the interior, as the walls and ceilings were built with chipboard panels.

A recent indoor air quality test was conducted, which states:
All measured values are in the green zone except for the formaldehyde exposure.
The legal limit here is 124µg/m³ and the measured value is at 270µg/m³].

My girlfriend has now obtained an offer from the company that also removed the asbestos in 2007.
This is about €50,000 and includes that all walls and ceilings will be treated with drywall panels and an aluminum sealant (a kind of foil).

Does anyone have experience with these values?
Is it necessary to do something on this scale?
Is it not possible to just remove the wallpaper, apply a sealing paint, and then put on new wallpaper or paint?

Simply air out more often and save 50k.

Thanks already

I spoke today with the expert who prepared the indoor air report and he said the same thing. Simply ventilate more often. If you don’t want to do that, then install a ventilation system.

Can others confirm this? Does anyone have a different opinion on this?

Hello

Formaldehyde is very volatile.
A high indoor air concentration after 40 years indicates that off-gassing will continue actively for the next few years and you will therefore continue to be exposed to a non-negligible amount.
In addition, you stay in the house every day – so you constantly breathe this air.
Total exposure = concentration * time. In your scenario, that adds up to quite a bit.

Is it certain that the formaldehyde comes from the particleboard? Or were there any other furniture / carpets etc. in the house?

What I would do: Send an email with the results to Okal Haus and ask what improvement measures they have recommended to their customers.
They must have been aware of the problem for 20 years.
Maybe they will say that non-woven wallpapers significantly reduce emissions into indoor air and that you can already achieve acceptable values that way.
If not, I would at least consider ventilation in rooms used for extended periods (bedroom, living room).

What does it smell like in your house? Don't you notice any unpleasant odor? By the way, formaldehyde plus moisture can accelerate or promote the formation of chloranisoles, which are responsible for the persistent musty smell of old prefabricated houses. Something like that could possibly still develop in your place. Therefore, aside from the health risks (there are limits for a reason), I would definitely carry out a renovation.