Biodegradable Chemicals

Good day All The general ​definition of ​biodegradable ​is anything ​that biologically ​degrades with ​time. This time ​can be 1000 ​years, 2days or ​any amount of ​time. So ​looking at this ​definition, ​then everything ​is technically ​biodegradable. ​ Some ​chemicals used ​for cleaning ​and disinfection ​(especially in ​food industry) ​has also been ​termed ​biodegradable.​ The WHO ​said Sodium-​diChloro-​Isocyanurate is ​a biodegradable ​chemical.  ​ So if certain ​chemicals are ​stamped ​biodegradable ​then this ​deviates from ​the general ​definition of ​biodegradability.​  ​ So what is ​actually the ​meaning of ​biodegradability ​when it is ​being used to ​stamp products ​as biodegradable.​ Is there a ​time to degrade ​which is used ​as reference. ​Example, ​anything taking ​>5 years is ​termed un-​biodegradable. ​Or what is the ​criteria to ​stamp a ​chemical as ​biodegradable? ​ Same as with ​labs that terms ​all parameters ​going through a ​0.45um filter ​as "soluble". ​But the same ​parameters ​termed soluble ​passing through ​a 0.45um filter ​is not soluble ​passing though ​a 0.03um filter.​ So the 0.45um ​size was used ​as reference to ​create the ​universal ​definition of ​soluble. ​