  The Extreme Energy Events (EEE) Project employs Multi-gap Resistive Plate
Chamber (MRPC) for studying the secondary cosmic ray muons in Extensive Air
Showers. The array consists of about 60 tracking detectors, sparse on Italian
territory and at CERN. The MRPCs are flowed with a gas mixture based on
$C_2H_2F_4$ and $SF_6$, both of which are fluorinated greenhouse gases with a
high environmental impact on the atmosphere. Due to the restrictions imposed by
the European Union, these gases are being phased out of production and their
cost is largely increasing. The EEE Collaboration started a campaign to reduce
the gas emission from its array with the aim of containing costs and decreasing
the experiment global warming impact. One method is to reduce the gas rate in
each EEE detector. Another is to develop a gas recirculation system, whose a
first prototype has been installed at one of the EEE stations located at CERN.
Jointly a parallel strategy is focused on searching for environmental friendly
gas mixtures which are able to substitute the standard mixture without
affecting the MRPC performance. An overview and first results are presented
here.
