A man exhales electronic cigarette vapor in a park in central Kiev, Ukraine, May 12, 2017. Reuters/Valentyn Ogirenko

The Austin city council Thursday voted to add electronic cigarettes, popularly known as e-cigarettes, to the list of tobacco products and banned its use in public places such as parks, restaurants and bars — effective from Monday, July 3, the Associated Press (AP) reported.

The decision is an updated version of an ordinance passed by the city council on Dec. 19, 2011, to ban tobacco smoking in public places. At the time, e-cigarettes gained a lot of popularity as they were not included in the ordinance. However, the city’s public health department officials were trying hard to get e-cigarettes included in the banned list.

Read: Are E-Cigarettes Safe? New Study Says Millions Who Use ‘Vaping’ As Tobacco Alternative Are Sucking In Formaldehyde

"We don't know what kinds of chemicals are in vape and whether or not it's safe and so we want to make sure that everybody has the right to breathe vape-free air and have their lungs protected," Christie Garbe, vice president and chief strategy officer for Austin Central Health said.

Garbe also said that smoking is the leading cause of preventable death in Travis County in central Texas, US News reported, citing AP.

The report also added that the American Cancer Society as well as the Food and Drug Administration (FDA) have warned about the presence of nicotine and other harmful chemicals in e-cigarettes.

According to the City Code Chapter 10-6-2, people are prohibited from using e-cigarettes and vaporizers in public places including parks, enclosed area inside a building or a facility owned, leased or operated by the government.

In case of violation of the law, a person is punishable under Section 1-1-99 by a fine of not more than $2,000.

The decision comes at a time when the U.S. is witnessing a drop in the number of people, especially teenagers, using e-cigarettes. A report based on a study conducted by the Centers for Disease Control And Prevention (CDC) was published recently in the Morbidity and Mortality Weekly Report. The study stated that the use of e-cigarettes among students dropped considerably from 4.7 million in 2015 to 3.9 million in 2016.

The study stated the number of middle and high schools students using e-cigarettes witnessed a sharp drop from 3 million in 2015 to less than 2.2 million in 2016.

Read: E-Cigarette Exploding Cases Mounting: Here’s How Dangerous Vaping Can Be

Though the use of e-cigarettes has declined in the past two years, it is still the most popular product among teens. While some people argue that e-cigarettes are a safer alternative to tobacco, others say that the chemicals used in liquids can cause lung diseases.

Apart from Austin, San Francisco too banned the sale of flavored nicotine-laced liquid, Tuesday, which is used in e-cigarettes and other flavored tobacco products, ABC News reported.

"We're focusing on flavored products because they are widely considered to be a starter product for future smokers," Supervisor Malia Cohen, who sponsored the bill, said.