  The Extreme Energy Events (EEE) Project, a joint project of the Centro Fermi
(Museo Storico della Fisica e Centro Studi e Ricerche "E.Fermi") and INFN, has
a dual purpose: a scientific research program on cosmic rays at ground level
and an intense outreach and educational program. The project consists in a
network of about 60 tracking detectors, called telescopes, mostly hosted in
Italian High Schools. Each telescope is made by three Multigap Resistive Plate
Chambers, operated so far with a gas mixture composed by 98% C$_2$H$_2$F$_4$
and 2% SF$_6$. Due to its high Global Warming Potential, a few years ago the
EEE collaboration has started an extensive R&D on alternative mixtures
environmentally sustainable and compatible with the current experimental setup
and operational environment. Among other gas mixtures, the one with helium and
hydrofluoroolefin R1234ze gave the best result during the preliminary tests
performed with two of the network telescopes. The detector has proved to reach
performance levels comparable to those obtained with previous mixtures, without
any modification of the hardware. We will discuss the first results obtained
with the new mixture, tested with different percentages of the two components.
