The food sanitizer in Fallout 3 has a passive effect on the player's food items as long as it is in the player's inventory. While in the player's inventory, the food sanitizer will increase the HP value restored by most consumables by 20%.
Equation: Initial HP x 1.2 (or 120%) = final amount of HP
Example: Nuka-Cola 10 HP x 1.2 = 12 HP
The food sanitizer has no effect on other properties of consumables and will not reduce any adverse effects, such as its radiation rating. It furthermore has no effect on purified water, the alien food found on Mothership Zeta, and the slop dished out in the Pitt (maybe because the latter is not regarded as food, or is past all sanitizing), but it does work on the Punga fruit from the Point Lookout add-on.
It is awarded after finding medicine in the Super-Duper Mart as part of the Wasteland Survival Guide quest, given by Moira Brown, along with the note sanitizer instructions. According to the sanitizer instructions, it will cleanse most food and drink in the user's inventory of harmful bacteria, allowing greater nutritional gain.
The food sanitizer not a quest item, and as such will be temporarily removed from your inventory in certain situations.
Fallout: New VegasEdit
While food sanitizers can be found in Fallout: New Vegas (prior to Patch 220.127.116.11x), they do not have as wide-sweeping an effect as in Fallout 3. The food sanitizer only affects two food items found in the game: junk food and bubblegum. In each case it adds a single point of health restoration when the item is used. Other than this minor effect, food sanitizers serve no real function and may be best sold for profit rather than kept.
Prior to Patch 18.104.22.168x, five food sanitizers could be found in the basement of the REPCONN test site. Four were found on the table in the room marked with "Food" signs, with the fifth found at the bottom of the stairs leading to the lower floor of the basement. The release of Patch 22.214.171.124x removed nearly all instances of the item. After completing Hard Luck Blues, choosing to save the vault inhabitants, and speaking to Horowitz, in the Aerotech Office Park, the player will be rewarded with this if they ask for a "vault trinket."
- Food sanitizers are also set up to work with Nukalurk meat which is not present in New Vegas' normal gameplay.
- Carrying more than one food sanitizer will negate the limited bonuses it provides. The item is only active if there is only one in the player's inventory.