As if the seemingly endless range of taxes and surcharges when we travel weren't enough, now the biggest international airport in Venezuela is charging passengers for the ultimate hidden extra-the right to inhale clean air.

The Simon Bolivar International Airport of Maiquetia in Caracas has taken it a step further by charging 127 bolivars ($18) as tax for passengers to breathe the airport's air from July 1, BBC News reported. It is to cover the cost of a newly-installed system which uses ozone to purify the building's air conditioning system, which in turn "eliminates contaminants," improves the environment and protects the health of passengers, press release from the Ministry of Water and Air Transport stated.

According to a statement on the airport's website, it is the first airport in South America and the Caribbean to use the technology, which it claims will eliminate bacterial growth to "protect the health of travellers," as well as deodorizing and sanitizing the building.

With tickets already deemed to be expensive and scarce due to the country's economic crisis, the required "breathing tax" for all domestic and international passengers has generated both outrage and humor, with many taking to social media to criticize the measure.

Radio presenter Daniel Martínez tweeted, "Could you explain to me the ozone thing in Maiquetia? The toilets don't have water, the air-con is broken, there are stray dogs inside the airport, but there's ozone?"

"Soon we will be charged for the 'good gas'" was another tweet - a rueful reference to the tear gas that the police often use on opposition protesters. The satirical news blog El Chiguire Bipolar ran the headline: "Maiquetia Airport unveils robot that puts you upside-down and takes your money."

While some Venezuelans feared that the "breathing tax" could turn out to be a new source of corruption, others saw it as evidence that the airport was cash-strapped, since most international airlines have reduced the number of flights to the country because of a financial dispute with the Venezuelan government.

Built in 1945, Maiquetia airport -- as it is known by locals -- is the main international air hub serving Venezuela.