Brass Toxicity?

[mete]

Modern pewter is usually lead free , sometimes called Britannia metal.
Brass [copper +zinc] will give off zinc fumes which is not good for you. Bronze usually does not have zinc. Brazing alloys can contain zinc.

BTW the silver bearing soft solder such as the 95Sn-5Ag is considered food safe so it can be used to repair pots and pans.

 

[Stacy E. Apelt - Bladesmith]

From a metallurgical point, there is little worry about any migration from the small lead percentage in the brass on a bolster. This is about as much a non-concern as the worry about drinking champagne from good crystal, which also contains a small percentage of lead. The lead will not really leach out much or easily. Leaching is a factor of environment and time. Water with a Ph below 7 and sitting in a pipe soldered with lead solder for long periods of time may leach out a few parts per billion ...but a piece of tomato that brushes across a brass bolster won't leach out any measurable amount of lead.

Unless you plan on boiling the knife in the tomato soup for an hour or two, there will be no issue with the lead in the brass. ( even then you would need the CDC lab to detect the amount absorbed by the soup.)

As said, you can always use a no-lead/zinc bronze or a no/low lead brass.....but it isn't an issue with the safe use of the knife.

 

[parbajtor]

From a metallurgical point, there is little worry about any migration from the small lead percentage in the brass on a bolster. This is about as much a non-concern as the worry about drinking champagne from good crystal, which also contains a small percentage of lead. The lead will not really leach out much or easily. Leaching is a factor of environment and time. Water with a Ph below 7 and sitting in a pipe soldered with lead solder for long periods of time may leach out a few parts per billion ...but a piece of tomato that brushes across a brass bolster won't leach out any measurable amount of lead.

Unless you plan on boiling the knife in the tomato soup for an hour or two, there will be no issue with the lead in the brass. ( even then you would need the CDC lab to detect the amount absorbed by the soup.)

As said, you can always use a no-lead/zinc bronze or a no/low lead brass.....but it isn't an issue with the safe use of the knife.

+1 on this and you're talking 1000 times more dilute than the blood level at which lead workers are required to undergo health surveillance.

BTW: The bronze shakes are not just down to toxicity of the zinc, but also because it's a fume (i.e. Nanoparticles). Nanoparticles are able to cross the HPV (Hepatic Portal Vein) as well as the blood brain barrier, so toxic effects are not counteracted by the body' defences. All welders will have a coating of whatever materials they weld on the outside of their brains. In the majority of cases this is not considered harmful because we currently don't live long enough for this to generate problems (lead & zinc aside). There may also be long term issues with Aluminium Welding because of a statistical correlation to Alzheimers (note, this has not been proved). However, aluminium welding is relatively new and "specialist" so the workforce exposed is still (statistically) small. We may know more in about 40 years time.
One of the health issues with nanotechnology is that the particle size means that relative toxicities of many chemicals will have to be revised. There are many defences the body uses to prevent stuff entering the bloodstream, all of them are bypassed by nanoparticles.

 

[felix24]

cool thanks for all the replies! i quess i was being a little over cautiouse . i wouldn't worry if the knife was for me, but i wanted to be sure before selling it to someone else.

Unless you plan on boiling the knife in the tomato soup for an hour or two, there will be no issue with the lead in the brass.

haha. somehow i don't think that's gonna happen....at least i hope not