Group 4 element doses and does not play any natural role inside the human body. Zirconium powder can cause irritation, but only contact with the eyes requires medical attention. OSHA recommendations for zirconium are 5 mg/m time weighted average limit and a 10 mg/m short-term exposure limit. Only limited data exists on the toxicology of hafnium. Group 4 element Group 4 is a group of elements in the periodic table. It contains the elements titanium (Ti), zirconium (Zr), hafnium (Hf) and rutherfordium (Rf). This group lies in the d-block of the periodic table. The group itself has not acquired a trivial name; it
Block (periodic table) column of the periodic table, also known as group 0 or group 18. Noble gases are also called as aerogens but this nomenclature of the group is not officially accepted by the IUPAC. All of the noble gases have full outer shells with eight electrons. However, at the top of the noble gases is helium, with a shell that is full with only two electrons. The fact that their outer shells are full means they rarely react with other elements, which led to their original title of "inert". Because of their chemical properties, these gases are also used in the