I don't think that is a very good example. A better example would be is there a safe compound with lead or arsenic or mercury (known toxic elements) you would want to take into your body?
https://en.wikipedia.org/wiki/Barium_sulfate#Radiocontrast_a...
"Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper. Approximately half (50%) of dental amalgam is elemental mercury by weight. The chemical properties of elemental mercury allow it to react with and bind together the silver/copper/tin alloy particles to form an amalgam."
https://www.fda.gov/medical-devices/dental-devices/dental-am....
Mercury salts are corrosive, organomercury compounds are highly neurotoxic and elemental mercury is relatively non-toxic if ingested.
The form of the element matters a lot.
[0]: http://www.isb-gym8-lehrplan.de/contentserv/3.1.neu/g8.de/id...
Even if thiomersal is more effective at killing bacteria than at killing humans, there are no doubts that it is also toxic for humans and for any other animals.
While the thiomersal dose injected together with a vaccine is small enough so that in most cases it will not cause damages before being eliminated from the body, the risks are not negligible.
To willingly inject yourself with poison, even in a quantity that hopefully will not hurt you, seems rather stupid.
Better alternative bactericides must be found for vaccine preservation.
That's why it wasn't justified.
Personally, I eventually discovered that my terrible problems with wearing contact lenses in the 1990's were caused by the thiomersal used as a preservative in the saline solution I was using. Given my known and tested reaction to having it in my eyes and on my skin, I would be very reluctant to have an injection that contained it.
Chloride is also deadly in high enough concentrations (or rather, in non-trace concentrations), but we also use low amounts of it in pool cleaners.
Mix the two and you get salt.
Obvious one is water. H - explody. O2 - burny. H2O - puts out fires, quenches your thirst, no longer a gas, not very reactive.
The point being made is that you can take dangerous elements and then create a compound that doesn’t share the properties of the elements.
So a counter argument is to show that’s not true for the elements that make up the compound for this blue dye.
Most corrosive substances release their effects on the surface they contact you, but toxic effects, especially the problematic ones, are way deeper.
The distinction is fairly important, especially regarding heavy metals.
Like hydrofluoric acid, for example. It's fairly easy to not notice you spilled some on your hand/arm until after it soaked through your skin, upon which the issue is systemic toxicity or at least bone damage. In contrast, sulfuric, nitric, and hydrochloric acids at any concentration up to azeotropic just cause burns and, for sulfuric acid, dehydration. There are no acute systemic risks from all but large-area burns, and even then it's mostly due to fluid loss which can be compensated for. (Yes, there are later risks due to loss-of-skin and skin graft surgery, but none of those complications try to have you pronounced dead you within a few hours of the spill.)
"Numerous other organizations have also publicly declared the safety and effectiveness of amalgam. These include the Mayo clinic,[21] the U.S. Food and Drug Administration (FDA),[22] Health Canada,[23] Alzheimer's Association,[24] American Academy of Pediatrics,[25] Autism Society of America,[26] U.S. Environmental Protection Agency,[27] National Multiple Sclerosis Society,[28] New England Journal of Medicine,[29] International Journal of Dentistry,[30] National Council Against Health Fraud,[31] The National Institute of Dental and Craniofacial Research NIDCR,[32] American Cancer Society,[33] Lupus Foundation of America,[34] the American College of Medical Toxicology,[35] the American Academy of Clinical Toxicology"
“A large retrospective cohort study found a significant association of mercury based fillings with the development of Parkinson's disease.”
(Reference to 2000 - 2008 study in Taiwan.)
Your link is interesting. It seems like the arguments against mercury amalgam being a problem include:
1) organizations like you listed saying don't worry
2) obvious scammers making a living blaming everything on fillings, even nonexistent ones
3) only 5% of people with fillings having elevated mercury in urine, particularly gum chewers
4) "hypersensitivity or allergy" are the "most likely health effects" but there is not clear evidence for or against autoimmune disorders caused by fillings.
It seems to me that it's perfectly conceivable, at the same time, that there is or has been a scam/cult of mercury fillings causing every possible problem, and at the same time, that they do do something to a minority of recipients that is different from acute mercury toxicity that we know about. There could be a combination of more than normal mercury released and more than normal sensitivity.
Something that would be interesting to research, I think, is the microbiome of people with and without different kinds of fillings. There's been some recent claim(s) about the bacteria that cause gingivitis being linked to Alzheimers.
"molecules are not the same as elements"
now repeat it with me
"molecules are not the same as elements"
Dental amalgam