update (29 Sept 2016): ACSA yesterday confirmed that "there are currently long queues observed at the various terminal security check points" at OR Tambo International Airport (JNB) in Johannesburg!
According to a travel update by South African low cost-carrier FlySafair, the airline has been advised this morning (28 Sept 2016) of potential industrial action on the part of the ACSA Airport Security Teams at OR Tambo International Airport (JNB) in Johannesburg. It is expected that movement through the security gates in the Domestic Departures Terminal (!) will be slower due to long queues. Passengers are advised to arrive as early as possible!