Sciencemadness Discussion Board

Mercury in batteries

tubelectric - 27-12-2013 at 14:20

Found some Panasonic alkaline batteries, more than 20 years old, that had leaked badly. I discarded them but now I started to think if I should have cleaned the box more thoroughly as older alkaline batteries may contain mercury. Wikipedia says that mercury is in amalgam form but could it convert to elemental form and leak out?

How about other battery types? Do silver oxide button cells still contain mercury?

Random - 27-12-2013 at 14:36

Button cells are far more dangerous as they did and still do (many of them) contain mercury compounds to make a functional cell.

Alkaline batteries as far as I know could have mercury contaminants which are harmful but not nearly in same amounts as these. As mercury is a heavy metal it poses a concern so today most alkaline batteries should contain a lot less mercury than before when it was not regulated.

I think you shouldn't be overly concerned but still clean it decently.

[Edited on 27-12-2013 by Random]

bfesser - 27-12-2013 at 14:51

Random, do you have proof that many button cells still contain mercury? I haven't seen any in a long long time (in the US).

Random - 27-12-2013 at 15:05

I have been researching this stuff on gold refining forum since they contain significant amounts of silver. Many probably still do contain mercury aswell because some guys there had to deal with it while recycling silver.

Now I checked on wikipedia that European Parlament decided to ban mercury containing button cells in 2013 and mercury containing products shouldn't be on the market by 2020. I am not sure about the US but I do believe one should still take them as a big concern, they are far less regulated than common alkaline batteries. It's only recently that mercury containing button cells are taking any regulations since they are better quality batteries than other button cell types.

macckone - 28-12-2013 at 08:58

It probably depends on manufacture date since the first non-mercury silver oxide battery wasn't made until 2004.

http://www.azom.com/article.aspx?ArticleID=2651

tubelectric - 29-12-2013 at 07:56

Found some button cells that may be more than 10 years old, and they had leaked a bit too... I wonder what stuff is still hiding in my parent's attic. :D

My main concern is if the mercury is in (or can become) pure elemental form in which it could leak out and evaporate. This is the case with actual mercury batteries but how about other types?

Random - 29-12-2013 at 08:18

Actually mercury could be present there as salts which is much more dangerous than metallic Hg. metallic Hg is mostly dangerous as vapors but Hg salts are different kind of hazard. You ingest water soluble salt, it goes right into your body.

Salt could get reduced by surrounding metal to metallic Hg which will probably form amalgam which would be as dangerous as dental amalgam. Caution is still necessary.

[Edited on 29-12-2013 by Random]

vmelkon - 29-12-2013 at 09:52

Quote: Originally posted by tubelectric  
Found some Panasonic alkaline batteries, more than 20 years old, that had leaked badly. I discarded them but now I started to think if I should have cleaned the box more thoroughly as older alkaline batteries may contain mercury. Wikipedia says that mercury is in amalgam form but could it convert to elemental form and leak out?


I do remember opening a Duracell AA from the late 1980 and seeing microscopic drops of mercury. I saw 1 drop that was larger then the rest and was obviously a liquid.

The 1980's and before were the boneheaded years. Companies did not write contains mercury and people threw everything in the trash.

Random - 29-12-2013 at 16:15

Quote: Originally posted by vmelkon  
Quote: Originally posted by tubelectric  
Found some Panasonic alkaline batteries, more than 20 years old, that had leaked badly. I discarded them but now I started to think if I should have cleaned the box more thoroughly as older alkaline batteries may contain mercury. Wikipedia says that mercury is in amalgam form but could it convert to elemental form and leak out?


I do remember opening a Duracell AA from the late 1980 and seeing microscopic drops of mercury. I saw 1 drop that was larger then the rest and was obviously a liquid.

The 1980's and before were the boneheaded years. Companies did not write contains mercury and people threw everything in the trash.


I never knew this was the case with older batteries. I guess you could spread some sulfur over the area if you are concerned.

tubelectric - 31-12-2013 at 14:21

Quote: Originally posted by Random  
Actually mercury could be present there as salts which is much more dangerous than metallic Hg. metallic Hg is mostly dangerous as vapors but Hg salts are different kind of hazard. You ingest water soluble salt, it goes right into your body.

Salt could get reduced by surrounding metal to metallic Hg which will probably form amalgam which would be as dangerous as dental amalgam. Caution is still necessary.

[Edited on 29-12-2013 by Random]


Yeah, salts can be very toxic but they don't evaporate, unlike metallic mercury. I have understood that if you wash your hands immediately after touching mercury salts you shouldn't have much to worry... or am I totally wrong? (And organomercury compounds should not exist in batteries...)
Quote: Originally posted by vmelkon  
Quote: Originally posted by tubelectric  
Found some Panasonic alkaline batteries, more than 20 years old, that had leaked badly. I discarded them but now I started to think if I should have cleaned the box more thoroughly as older alkaline batteries may contain mercury. Wikipedia says that mercury is in amalgam form but could it convert to elemental form and leak out?


I do remember opening a Duracell AA from the late 1980 and seeing microscopic drops of mercury. I saw 1 drop that was larger then the rest and was obviously a liquid.

The 1980's and before were the boneheaded years. Companies did not write contains mercury and people threw everything in the trash.


Now that sounds nasty. Yeah those batteries didn't have *any* notes about mercury on them. They may have been leaking unnoticed for years so if there has been liquid mercury it has likely evaporated... The good thing is that I have searched through most places where I might have old batteries and haven't found more.


...however, I found a flashlight with Duracell 3LR12 (flat 4.5V) battery and it had leaked. :D Funny thing, I think every 4.5V Duracell that I've used since 2003 maybe, started to leak at some point. Some were already leaking when I unboxed them.

[Edited on 31.12.2013 by tubelectric]

Random - 31-12-2013 at 19:14

Actually touching mercury salts is not at all advisable especially with bare hands.

Now everything depends on the scale we are talking about. This isn't much and mercury salts would also form amalgams with metal casing over time. Not much would be evaporated.