Information only
Content is provided for general information and education. It is not professional, legal, medical, engineering, radiological-safety or investment advice. Always consult the cited primary sources and qualified professionals before making decisions.
Accuracy
We work from published sources and aim for accuracy, but errors and omissions are possible and figures change over time. The site is provided as is, without warranties of any kind, and to the extent permitted by law we accept no liability for loss arising from its use.
Calculators
Calculators are teaching aids using simplified formulas. Their output must not be used for licensing, safety or financial decisions.
Citing this site
You may quote short excerpts with a link back to the source page. Please cite the primary sources listed in each article wherever possible.
External links
External links are provided for reference. We do not control and are not responsible for the content of other websites.