"Police are still on the scene to monitor the situation and will take action if [necessary]," Lieutenant-Colonel Andre Traut said on Tuesday.
The five would appear in court once charged.
Acting airport spokesperson Deborah Francis said the group apparently pretended to be passengers and carried plastic bags through to the domestic and international departures terminal at about 1.30pm.
"It happened literally within a few split seconds. They threw it, jumped back into the cars and sped off," she said.
The group was then apprehended by police. Francis said the airport was a national key point.
"The scene was handed over to the South African Police Service, and the area has been demarcated. Once they've assessed everything, there are Hazmat consultants that will clean up."
Francis said the incident had not resulted in any operational delays, and two entrances in the terminal hall remained open.
Two weeks ago, 183 people were arrested on public violence charges at the Esplanade train station in Woodstock for carrying portable flush toilets and human waste in blue municipal bags placed in milk crates.
They apparently also sang freedom songs which included a reference to Western Cape premier Helen Zille as a dog.
The group appeared in court, was released on warning, and told to return on August 2 after further investigation.
The state was unsuccessful in its bid to block bail for Yandani Kulati, Thembela Mbanjwa and former councillor and ANC Youth League member Andile Lili.
At the start of the month, a group of people in Khayelitsha threw human waste at a bus and cars used for transport to a green economy event hosted by Zille.
The day before, two men dumped faeces on the steps of the Western Cape legislature in a protest about portable flush toilets.
The men identified themselves to the Cape Argus newspaper at the time as Lili and ANC proportional councillor and youth league member Loyiso Nkohla.
The protests were linked to the apparent dissatisfaction by some communities over sanitation in informal settlements and the rolling-out of portable flush toilets.
Youth league national task team co-ordinator Magasela Mzobe said the youth league distanced itself from faeces throwing, but not from raising poor service delivery.
"We are [telling] them that there is a better way that we can employ in raising the plight of our people without having to throw faeces all over the province," he said.
"If they do not listen to that, we are forced then to look at the internal processes of disciplinary action." – Sapa