became the first state to implement e-cigarette minimum legal sale age law (mlsa) and comprehensive indoor use ban in workplaces, restaurants, and bars. that same year, minnesota imposed the first e-cigarette tax in the country. six years later, the food and drug administration's center for tobacco products (fda-ctp) deemed e-cigarettes to be tobacco products. in may 2016, the fda-ctp made the following requirements: e-cigarettes are required to carry a warning label, a national e-cigarette mlsa of 18 was put in place, and the fda-ctp must eventually approve all e-cigarette products through a pre-market application process. effective 8 august 2016, all us states will follow the same, uniform federal guidelines. with an absence of federal regulations, many states and cities had adopted their own e-cigarette regulations, most commonly to prohibit sales to minors, including maryland, kentucky, minnesota, new jersey, new hampshire, tennessee, utah, wisconsin, and colorado. other states are considering similar legislation. several us cities and states have enacted laws that increased the legal age to purchase e-cigarettes to age 21. as of 2014, some states in the us permit e-cigarettes to be taxed as tobacco products, and some state and regional governments in the us had extended their indoor smoking bans to include e-cigarettes. governor arnold schwarzenegger vetoed a bill that would regulate the sale of e-cigarettes within the state on grounds that "if adults want to purchase and consume these products with an understanding of the associated health risks, they should be able to do so." a review of regulations in 40 u.s. states found that how a law defines e-cigarettes is critical, with some definitions allowing e-cigarettes to avoid smoke-free laws, taxation, and restrictions on sales and marketing. fewer policies have been created to restrict vaping indoors than with cigarette smoking. many local and state jurisdictions have recently begun enacting laws that prohibit e-cigarette usage everywhere that smoking is banned, although some state laws with comprehensive smoke-free laws will still allow for vaping to be permitted in bars and restaurants while prohibiting e-cigarettes in other indoor places. as of august 2016, the united states navy is considering banning e-cigarettes. a 2017 report stated "as of 2 october 2015, five us states and over 400 counties have implemented some form of restriction of ecig use indoors. international policies are more varied with certain restrictions for ecig use in uk airports and trains and reports of complete ecig bans in indoor public places for malta, belgium and spain". san francisco banned the sale of flavored e-liquids in 2018. they are the first city in the us to enact such a ban. in november 2018, the fda required e-cigarette manufacturers not to sell e-cigarette products online without strict age verification. it was also requested e-cigarette suppliers to end bulk purchasing of e-cigarettes and to remove flavored e-cigarettes from stores. in january 2020, the city of san francisco banned e-cigarette (but not traditional cigarettes). by january 2020, twenty states had implemented e-cigarettes taxes, sixteen had comprehensively banned indoor use of the product, and eight had imposed temporary restrictions on the sale of all e-cigarettes or flavored e-cigarettes. policy evaluation studies studies that examine the impact of e-cigarette taxes on use of e-cigarettes and traditional cigarettes have found that e-cigarette taxes increase cigarette use across different populations (adults, children, pregnant), thus providing evidence that the two products are economic substitutes. along the same line, another study found that e-cigarette minimum legal purchase age laws increase cigarette use among 12 to 17 years old, suggesting that e-cigarettes are displacing youth smoking rather than acting as a gateway to youth smoking. regarding indoor vaping regulations, one study found that it increased prenatal smoking by about 0.8 percentage points had no significant impact on birth outcomes. criticism of vaping bans critics of vaping bans state that vaping is a much safer alternative to smoking tobacco products and that vaping bans incentivize people to return to smoking cigarettes. for example, critics cite the british journal of family medicine in august 2015 which stated, "e-cigarettes are 95% safer than traditional smoking." in 2019, san francisco's chief economist, ted egan, when discussing the san francisco vaping ban stated the city's ban on e-cigarette sales will increase smoking as vapers switch to combustible cigarettes. critics of smoking bans stress the absurdity of criminalizing the sale of a safer alternative to tobacco while tobacco continues to be legal. prominent proponents of smoking bans are not in favor of criminalizing tobacco either, but rather allowing consumers to have the choice to choose whatever products they desire. in 2022, after two years of review, the food and drug administration (fda) denied juul's application to keep its tobacco and menthol flavored vaping products on the market. critics of this denial note that research published in nicotine and tobacco research found that smokers who transitioned to juuls in north america were significantly more likely to switch to vaping than those in the united kingdom who only had access to lower-strength nicotine products. this happens as the biden administration seeks to mandate low-nicotine cigarettes which, critics note, is not what makes cigarettes dangerous. they also note that vaping does not contain many of the components that make smoking dangerous such as the combustion process and certain chemicals that are present in cigarettes that are not present in vape products. notes in india, e-cigarettes are mostly unregulated and are technically illegal to sell, as they have not received approval from the central drugs standard control organization (cdsco). according to government data, as of july 2019, there were over 460 e-cigarette brands available in the indian market utilizing varying methods of nicotine delivery and over 7,700 flavours of e-liquids. the ministry of health and family welfare issued an advisory to restrict the advertisement of e-cigarettes in august 2018. the cdsco notified all state drug controllers on 22 february 2019 that ends products were not approved for sale, and asked them to ensure that the sale of such products was prohibited. there was confusion over what law could be applied to regulate e-cigarettes. on 1 june 2019, experts at a drug consultative committee meeting concluded that ends devices fell under the definition of "drug" under section 3(b) of the drugs and cosmetics act, 1940. the state drugs controller of the state of punjab declared e-cigarettes with nicotine as an unapproved drug in 2013. on 7 april 2016, a district court in the punjab sentenced a man to 3 years imprisonment and a fine of ₹1 lakh (us$1,300) for selling e-cigarettes. this was the first ever conviction in india concerning e-cigarettes. the states of bihar, haryana, karnataka, kerala, jammu and kashmir, maharashtra, mizoram, punjab, uttar pradesh and the union territory of chandigarh have declared e-cigarettes as an unapproved drug under the drugs and cosmetics act and rules, 1945, and can prosecute sellers under the drugs and cosmetics act and rules, 1945.