The use of non-renewable energy resources (NRER) is relevant
for the production of EPS material (i.e. z150 MJ every 100 porthole
spacers). The reasons for that are: the use of non-renewable
feedstock for its production (i.e. oil and natural gas) and the use
of energy (electricity and heat), mainly consumed in the expansion
process and largely based of fossil fuels (European electricity mix).
This in turn also affects acidification (AP), since substances such as
NOx, SO2 etc. are emitted into the atmosphere during fossil fuel
combustion.