How to blacken brass ???

[AgX]

This potion contains toxic Seleniumdioxide.

 

[grat]

This potion contains toxic Seleniumdioxide.

While true, good old H2O can be toxic as well. Rather than just spread fear, try being helpful:

ICSC 0946 - SELENIUM DIOXIDE

Which says, in general terms, it's hazardous if (mis)handled without proper precautions. The compound also appears to include muriatic acid (hard to read), which is far more deadly. But we don't know how much of each is in there, so it's difficult, without an actual MSDS, to judge how dangerous it is.

However-- it also has very clear instructions on how to handle it safely, so being alarming for the sake of being alarming is somewhat.... alarming.

 

[AgX]

I am not alarming for the sake of alarming.
But advising a compound containing a highly toxic chemical, with the added problem of how to dispose of the bath as it being environmental toxic too, is no good idea, when there are much much more benign compounds, even been advised twice in that thread. And your hint to muriatic acid is not well founded. Let alone your statement of water being toxic...
To me such is advising for advising sake.

And I do not remember having come across a selenium recipe in dedicated brass blackening engineering-literature. But I might glance through it when I got such at hand again.


It would have been a different case if that selenium compound had been advised as being significantly superior in result to what already had been advised, and hinting at its special formula and the inherit issues.

 

[grat]

... but hydrohydroxic acid is in fact, an acid, a powerful solvent, and can be fatal if inhaled in large quantities. Those are all facts.

They're somewhat misleading, but your plain post of "contains toxic selenium dioxide" is as well.

Why is my 'hint to muriatic acid' not well founded? I can literally see "uriatic acid" on the ingredients label, and it's a common acid for etching metals.

Finally, if you read the label, you'll see there are directions for handling, as well as returning the used chemical to the bottle, and storing safely. Ultimately, when it needs to be disposed of, like most hazardous chemicals around the house, it should be disposed of via local hazardous waste handling.

I assume you post similar warnings any time someone mentions selenium toning their prints?

 

[AgX]

Hydrochloric acid is even natural part of the human body, its danger man's health and to envirinment is much more a matter of comcentration, in contrast to Selenium dioxide.

Yes, I would post warnings about Selenium toning, but I even posted at least twise within the last two years about Selenium that some warnings given at this forum are over the top. Thus it all depends...


But you still not reacted on my main point:
if there is a less toxic, less environmenmtal effect substance of similar usage, then to prefer that.