Back to Ganoksin | FAQ | Contact

LoS safety precautions


#1

something I have been meaning to ask, and as LOS is being discussed,
could I jump in here and ask a safety question, as to how dangerous
it is, either in lump form or with added water.

I know of one supplier who will only send LOS as a hazardous
shipping item, and another who sends it by normal carrier.

What safety precautions should you take when using LOS to blacken
silver and how should you dispose of the solution.

tks.
Judy P


#2
What safety precautions should you take when using LOS to blacken
silver and how should you dispose of the solution. 

It’s not especially dangerous. Use with decent ventillation simply
because the stuff stinks and some people react to that. Not that the
fumes are especially toxic, but still annoyingand in high
concentrations or for prolonged periods, maybe not healthy. So
ventilate reasonably. Paranoia not required or indicated. Beyond
that, don’t drink or eat it. Dispose of used solution down the
drain. Not hazardous and it degrades quickly enough so far as I know.

Peter


#3

Here are a couple of MSDS sheets for LOS otherwise known as potassium
polysulfide. One gives it a low health hazard rating and one gives it
a high hazard rating. There is a range of danger levels assigned by
different companies to this chemical. One MSDS I looked at stated
that there is not enough in the literature to assign
accurate health hazard data to it. So it is hard to make a informed
decision. So I would suggest to minimize contact with it. Use the
typical shop safety practices and equipment. Specifically safety
glasses, gloves and good ventilation. Don’t mix it with other
chemicals. It is a base and is moderately corrosive, you definitely
don’t want to ingest or get it in your eyes or lungs.

http://tinyurl.com/mjxjh6
http://tinyurl.com/kkxwsf

James Binnion
James Binnion Metal Arts


#4

As it happens, I have been oxidizing some silver and copper jewelry
in liver of sulphur the past few days, so I thought I’d weigh in on
this too. I let it sit 24 hours or more. It loses it’s color and
odor, and forms a white skin on the top of the liquid. I tried
pouring in some soda to neutralize it further, but it did not foam at
all - so just by sitting it seems to neutralize enough. Then I added
lots of water to it before pouring down the drain, and followed with
more water for quite a while. I’ve read variousplaces that it’s safe
to do it that way.

Linda Gebert
www.lindagebert.com


#5

Most importantly, do not place a piece(s) in LOS if they have been
pickled and the pickle has not been sufficiently neutralized. Stated
another way…if you pickle your work, neutralize the acid of the
pickle before applying a LOS patina.

The combination of acid and LOS is deadly.

Linda Kaye-Moses


#6
The combination of acid and LOS is deadly. 

many thanks to everyone who has replied to my question about safety
and LOS. I feel much more reassured about what I am working with now
and confident to proceed with due caution.

Though I would always clean my piece very carefully after pickling,
I am curious to know in what way is the combination of acid and LOS
deadly.

thanks again. Judy


#7

Liver of sulphur will not turn clear as fast if kept in a brown glass
bottle or the brown plastic bottle hydrogen peroxide comes in. You
still need to just make small amounts as you need it, it just lasts a
few days longer.

Richard Hart G.G.
Jewelers Gallery
Denver, Co.


#8
The combination of acid and LOS is deadly. 

or at least smelly. It could result in the formation of hydrogen
sulphide, a rather stinky (rotton eggs) gas. And that is indeed a
quite toxic gas. But in real world terms, it takes more than a trace
of the stuff to be deadly. You’d have to be mixing significant
amounts of acid, more than a trace of residual pickle on a piece,
with significant amounts of LOS before you could generate enough of
the gas to actually be deadly. Very tiny amounts, sucn as you’d
likely get from having a little pickle left on your work, will make
an unpleasant smell which can annoy you. But it’s not likely to
actually harm you… And if you do generate more than a trace, you’ll
know it. Like I said, hydrogen sulphide is very smelly stuff…

Peter


#9

Hi Linda,

Most importantly, do not place a piece(s) in LOS if they have been
pickled and the pickle has not been sufficiently neutralized.
Stated another way...if you pickle your work, neutralize the acid
of the pickle before applying a LOS patina. 

Good to see you on Orchid. May I ask where the los/acid information
can be found?

Thanks, Andy


#10
I let it sit 24 hours or more. It loses it's color and odor, and
forms a white skin on the top of the liquid. I tried pouring in
some soda to neutralize it further, but it did not foam at all - so
just by sitting it seems to neutralize enough. 

Liver of sulfur is a base so putting soda (sodium bicarbonate) is
not going to neutralize it. Just dilute it and pour it down the
drain.

James Binnion
James Binnion Metal Arts


#11
Most importantly, do not place a piece(s) in LOS if they have been
pickled and the pickle has not been sufficiently neutralized.
Stated another way...if you pickle your work, neutralize the acid
of the pickle before applying a LOS patina.
The combination of acid and LOS is deadly. 

We ought to have one of the chemists weigh in on this but I think if
you mix LoS and some acids you will indeed release hydrogen sulfide
gas which is deadly. But the tiny bit of acid that might be on most
work is not going to release enough to be a problem to anyone. But
if you did something like trying to lower the pH of the LoS solution
to neutral by adding an acid to it you could indeed release enough to
do your self in.

James Binnion
James Binnion Metal Arts


#12

Hi Andy,

After so many years of ‘doing and reading’ I have to admit that I
don’t recall where I first heard/read about the nasty effect of
adding LOS to a pickled piece without first neutralizing the acid.
However, I believe that the first person I heard talk about this
effect was Charles (do chime in here Charles if you’re reading
this).

And, backatcha, it’s always good to ‘hear’ your voice on Orchid.

Hope all is well with you,
Linda Kaye-Moses


#13
I am curious to know in what way is the combination of acid and
LOS deadly. thanks again 

Most acids react with most sulphides to produce the gas hydrogen
sulphide, which is indeed deadly and equally comparable with
hydrogen cyanide in firly large doses.

It is poisonous because it combines easily with blood haemaglobin,
which provides oxygen to the vital parts of the body, thus starving
that part of the body of oxygen, especially as this cannot be
reversed. About three months ago two workmen in New Zealand went
into a sewer, died and could not be resusitated even after a quick
rescue.

The microscopic amount of the gas produced in cleaning the black
tarnish from small jewellery can be discounted as a hazard.I do
agree that Tarnex is better than any acid, however.

I have spent most of my life in chemistry labs which always stink
and I am 88 next month. The town of Rotorua in NZ stinks of the gas,
all the time, every day; but they still grow old there!

Moral? Just keep out of the sewer.

Cheers for now,
JohnB of NZ


#14
The microscopic amount of the gas produced in cleaning the black
tarnish from small jewellery can be discounted as a hazard. I do
agree that Tarnex is better than any acid, however. 

Good to hear a voice of reason and experience. Hang in there John;
your voice is needed and appreciated. And a happy birthday
anniversary in advance.

KPK