A simple model for the thermal decomposition of amorphous cellulose is prop
osed that rationalizes the effect of water in promoting the charring proces
s at the expense of volatilization. Simulations of mass-loss histories and
product evolution are shown to be consistent with various experimental obse
rvations in the literature. Under char-promoting conditions where heat tran
sfer is limited, anomalous thermal effects are predicted which indicate tha
t char formation may not always be desirable in fire-inhibiting treatments
of or strategies for cellulosic materials.