Common additives to cigarettes

Question

I have heard that common cigarette brands add additives to the tobacco in cigarettes (not in the filter) and I've heard many people use this as an excuse that it is safer to grow and roll your own.

Do most major tobacco companies add a bunch of extra ingredients to cigarettes?

Here is one example:

There are more than 4,000 ingredients in a cigarette other than tobacco. Common additives include yeast, wine, caffeine, beeswax and chocolate. Here are some other ingredients:

• Ammonia: Household cleaner

• Angelica root extract: Known to cause cancer in animals

• Arsenic: Used in rat poisons

• Benzene: Used in making dyes, synthetic rubber

• Butane: Gas; used in lighter fluid

• Carbon monoxide: Poisonous gas

• Cadmium: Used in batteries

• Cyanide: Deadly poison

• DDT: A banned insecticide

• Ethyl Furoate: Causes liver damage in animals

• Lead: Poisonous in high doses

• Formaldehiyde: Used to preserve dead specimens

• Methoprene: Insecticide

• Megastigmatrienone: Chemical naturally found in grapefruit juice

• Maltitol: Sweetener for diabetics

• Napthalene: Ingredient in mothballs

• Methyl isocyanate: Its accidental release killed 2000 people in
  Bhopal, India in 1984

• Polonium: Cancer-causing radioactive element

Answer 1

Yes, tobacco companies add additives to cigarettes, and those additives have an effect.

References:

Pharmacological and Chemical Effects of Cigarette Additives, Michael Rabinoff, Nicholas Caskey, Anthony Rissling, and Candice Park

American Journal of Public Health, November 2007, Vol 97, No. 11 DOI: 10.2105/AJPH.2005.078014

We investigated tobacco industry documents and other sources for evidence of possible pharmacological and chemical effects of tobacco additives. Our findings indicated that more than 100 of 599 documented cigarette additives have pharmacological actions that camouflage the odor of environmental tobacco smoke emitted from cigarettes, enhance or maintain nicotine delivery, could increase the addictiveness of cigarettes, and mask symptoms and illnesses associated with smoking behaviors.

For more information, here is a non peer-reviewed study, but the results of a in-depth literature review of the additives that might be found in cigarettes and the data about them.

Effects of Ingredients on Cigarette Smoke Composition and Biological Activity: A Literature Overview, Thilo Paschke, Gerhard Scherer and Wolf-Dieter Heller, Beiträge zur Tabakforschung International/Contributions to Tobacco Research Volume 20, 3 August 2002

The format of this work is that of an uncommented reference paper rather than a critical scientific review. Therefore, the mention of an ingredient in this survey does not imply that it is used by the tobacco industry or that it is covered by any existing national regulations.

...

Nowadays, different forms of regulations and disclosures exist in several countries of the European Union (e.g., France, the United Kingdom and Germany) as well as in the United States (list of 599 ingredients [TR Staff Report, 1994]), which control the use of ingredients for the manufacture of tobacco products

None of this proves that it is safer to roll your own. Even if it is safer, it is not safe. (It is 2011, not 1967, so I don't think I need to reference this claim!)