Is there an international standard for rating the danger of chemical elements?

I'm writing a small little tool (something like an interactive periodic table) and I wanted a good "guesstimate" of the danger of certain elements, to visualize across said table.


I could go and guess by manually looking up the physical / chemical / health / other effects of every element, but that would take an obscene amount of time and effort, not to mention it wouldn't be very accurate / precise.


My question is, **is there a standard or "list" recognized internationally as a good scale of the danger of certain elements?**


I know of the NFPA 704 Hazard Classification diamond, and while that would be perfect for my use, it doesn't classify every element, mainly just chemical compounds + a few noteworthy elements.


For example, I could find an NFPA 704 for just about every major compound of arsenic, but not pure arsenic (the element), which would be a pretty obviously dangerous element.




You can check the European [ECHA Database](https://echa.europa.eu/en/information-on-chemicals) (or the corresponding original CLP Regulation), which uses the Globally Harmonised System (GHS) managed by the United Nations, if it contains the relevant elements.


For [arsenic](https://echa.europa.eu/en/information-on-chemicals/cl-inventory-database/-/discli/details/85010), you would find that it's


* Toxic if swallowed (H301)
* Toxic if inhaled (H331)
* Very toxic to aquatic life (H400)
* Very toxic to aquatic life with long lasting effects (H410)


![skull and crossbones (GHS06)](https://i.stack.imgur.com/wsKWz.gif) ![environment (GHS09)](https://i.stack.imgur.com/WThBu.gif)


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