http://en.wikipedia.org/wiki/Denatured_alcohol
Denaturing alcohol does not chemically alter the ethanol molecule. Rather, the ethanol is mixed with other chemicals to form an undrinkable mixture.
Different additives are used to make it difficult to use distillation or other simple processes to reverse the denaturation. Methanol is commonly used both because of its boiling point being close to that of ethanol and because it is toxic.
Denatured alcohol and its manufacture are a public policy compromise. The supply and demand for denatured alcohol arises from the fact that normal alcohol (which in everyday language refers specifically to ethanol, suitable for human consumption as a drink) is usually very expensive compared to similar chemicals, being highly taxed for revenue and public health policy purposes (see sin tax). As a result, if pure ethanol were made cheaply available as a fuel or solvent, people would drink it.
Denatured alcohol provides a solution to permit legitimate use and manufacture of ethanol, whereby cheap ethanol can be made available for non-consumption use without the risk of it being converted for consumption.
OK...so, denatured alcohol, wood alcohol, is naturally toxic... and you are saying that ethanol manufacturers add toxic compounds to fuel-grade ethanol so it cannot be utillized in the process of making distilled adult beverages.
We used to burn methanol in our 2-cycle go-cart engines in the 1960’s...sure did smell good.