# What is that white crusty stuff on batteries? **URL:** \ **Category:** Factual Questions\ **Created:** [July 11, 2010, 1:58am UTC](https://boards.straightdope.com/t/what-is-that-white-crusty-stuff-on-batteries/546267 "2010-07-11T01:58:29Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![YogSothoth](https://avatars.discourse-cdn.com/v4/letter/y/8edcca/32.png) [@YogSothoth](https://boards.straightdope.com/u/YogSothoth)\ **Post date:** [July 11, 2010, 1:58am UTC](https://boards.straightdope.com/t/what-is-that-white-crusty-stuff-on-batteries/546267/1 "2010-07-11T01:58:29Z")
When batteries are used for a long time in something like a remote, then you open the back to change it and there’s this white crusty stuff on the edges. What is that? Is it dangerous? ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [July 11, 2010, 2:16am UTC](https://boards.straightdope.com/t/what-is-that-white-crusty-stuff-on-batteries/546267/2 "2010-07-11T02:16:47Z")
This might help —\> [http://www.needbattery.com/Articles/Cleaning-up-the-battery-leakage-in-flashlight.html](http://www.needbattery.com/Articles/Cleaning-up-the-battery-leakage-in-flashlight.html) ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [July 11, 2010, 2:18am UTC](https://boards.straightdope.com/t/what-is-that-white-crusty-stuff-on-batteries/546267/3 "2010-07-11T02:18:44Z")
it is slightly corrosive to the electronics and skin. open the device over a sheet of newspaper and remove the batteries. use a knife to scape any crust off the battery contacts of the device. wiping battery compartment and battery contacts with moist paper towel if residue has got on them.wrap up batteries and crust and discard. wash hands and knife.