“One can fulfill a Torah obligation when
lighting the Chanukah menorah. The
Torah mitzvah one fulfills is
“V’nishmartem me’od
l’nafshoseichem” (Devarim 4:15) which
stipulates that one must take safety
precautions and protect oneself and
others. Fire is extremely dangerous and
many people have been injured or killed,
R”l, when proper safety measures were
not taken regarding Chanukah flames.
The other mitzvos of Chanukah are
d’Rabbanan.”
From: http://www.theyeshivaworld.com/news/headlines-breaking-stories/202924/chanukah-an-in-depth-overview.html