To answer your question, you should be safe for most electronic work, but it is good safety practices to respect all electric circuits and take fundamental safety precautions.
The amount of current a person can handle depends upon many factors. Current quantity, current type, body mass, broken skin, path and length of contact time, etc.
Many similar charts exist. From Science online - Benefits and dangers of electricity
The only scientific study I know of is Charles Dalziel, 1961 (Inventor of the GCFI). Ultimately, this is where the 100mA 60Hz AC and 500mA DC comes from.
As can be seen from the chart DC levels are 3-5 times safer than 60Hz AC.
The first 5 rows are based upon human tests (check out pictures at end of report), while the last is estimated from experiments on dogs. It would be highly unethical to do these tests today.
Fibrillation (100mA-200mA) can be deadly because it sets the muscles of the heart pumping randomly requiring defibrillation as the only way to restart the heart. A higher current will cause serious injuries but the heart/lungs may start once the person is removed from the shock hazard.
Even currents as low as 16mA 60Hz AC and 76mA DC can cause unconsciousness and death if the exposure is long enough as the individual is frozen to the circuit. Your brain, hearts and lungs work, but you cannot let go. All of the muscles of your body are contracted. Think really, really good frozen tag.