Acceptable Daily Intake
Acceptable Daily Intake (ADI) is the "Quantity of a food additive that can be ingested daily, over a lifetime, without any risk (expressed in milligrams additive per kilogram body weight)." 
The term Acceptable Daily Intake (ADI) is used by the World Health Organization (WHO) and "other national and international health authorities and institutes" to describe exposure limits of toxic chemicals. 
The term "tolerable daily intake" (TDI) is used by the International Program on Chemical Safety (IPCS) and the "new term 'permitted daily exposure' (PDE) is defined in the present  guideline as a pharmaceutically acceptable intake of residual solvents to avoid confusion of differing values for ADI's of the same substance." 
"For an ADI, toxicity studies are conducted to determine a No Observed Effect Level or a No Observed Adverse Effect Level (NOAEL). The studies would be selected to represent the expected types of exposure. For colours, this would be oral exposure. A safety factor is then added to take into account species difference between test animals and humans and variability between individuals. This is typically taken as a 100 fold factor." 
"The bodies which set the ADIs are the WHO/FAO Joint Expert Committee on Food Additives (JECFA) at a global level, the Scientific Committee for Food (SCF) at EU level and/or a national body."