Delhi chokes every year in November and December.

As winter peaks, low wind speeds in the land-locked state lead to high concentration of air pollutants. Hospitals then swell with patients with respiratory illnesses. The Central Pollution Control Board frequently issues warnings asking residents to stay indoors.

But indoors isn’t safe either, with dust and smoke often exceeding permissible levels. This has spawned a pollution-combating industry, selling products from indoor plants to surgical face masks.

One anti-pollution segment that has seen a phenomenal rise in recent years is air purifiers.

According to estimates from the London-based market research firm Euromonitor, the segment recorded sales of roughly Rs 116 crore in 2017. That’s more than twice the 2014 sales of Rs 50 crore.

India’s upwardly mobile and affluent households shell out anything between Rs 7,000 and upwards of Rs 50,000 for these products. The category is expected to grow at a compounded annual rate of 14.5% till 2022, estimates Euromonitor.

Not surprisingly, from just a few local companies in the 1990s, the air purifier boom has now seen several foreign brands flooding the market. This includes Dyson, Philips, Honeywell, Hitachi, Xiaomi, Sharp, and HUL’s Pureit. They compete with local players like Kent, and Bluestar besides Eureka Forbes.

Yet, a mere 200,000 purifier units were sold in India in 2017, during which time, China saw nine million units being sold, according to Euromonitor.

Marketers Quartz spoke to explain why selling air purifiers in India is still an uphill task.

Choked sales

The primary bottleneck is a lack of awareness. “There is much work to be done when it comes to educating people that indoor air is as polluted as outdoor air. Air purification is still a very Delhi-centric phenomenon,” said Gulbahar Taurani, senior director and head of marketing for personal health at Philips India. The Dutch consumer goods maker launched its first purifiers in India in 2014.

Secondly, the market in India lacks standardisation. The absence of regulatory oversight has left the market littered with lower-priced inferior products.

Up to 50 brands are currently available in the market, eating into the share of the organised players. This has pushed the big players to run aggressive marketing campaigns, push for standardisation, and to look beyond Delhi, their biggest market.

The early days

In 2015, local authorities in Delhi declared a pollution emergency, citing the city’s toxic air. This is when a slew of air-purifier makers first sensed an opportunity. Philips, Blueair, and Kent, among others, launched new products that year.

A similar pollution crisis in 2013 had pushed companies in China towards large scale manufacturing. So in the early days, appliance makers in India took cues from China.

“When we started hearing about pollution in China, that was the tipping point. We started getting concerned about air quality,” Sudhir Pillai, general manager at Honeywell, told Quartz. The American company rolled out a range of purifiers in 2016 with prices ranging between Rs 30,000 and Rs 40,000.

In the past two years, brands have fine-tuned their products, bringing out even compact and inexpensive units.

Quality standards

Browse through an e-commerce website in India today and you will be welcomed by offers and advertisements from multiple air purifier brands selling ionisers, car purifiers, and humidifiers. The prices range from Rs 5,000 to Rs 50,000.

This influx of local brands has left the incumbents perplexed. They blame the low entry standards for this.

Most consumer goods sold in India – from laptops to ovens – need to be certified by the Bureau of Indian Standards. But not air purifiers. “This essentially means that anyone can import a product from China, slap a label on it and sell it,” said Shashank Sinha, chief transformation officer at Eureka Forbes.

In India, established players make air purifiers based on Western certifications. Most brands are certified by the US’s Association of Home Appliance Manufacturers and the European Centre for Allergy Research Foundation.

This has pushed some large brands like the UK-based Dyson to consider drafting standards in association with authorities in India. “Dyson is engaged with BIS [Bureau of Indian Standards], and looking at experts with expertise in this area. We also work with an external advisory board of respiratory specialists to help guide our product development,” a company spokesperson told Quartz over e-mail.

Some standards could come into play by next year, indicated Eureka Forbes’s Sinha without sharing details.

Price and penetration

The lack of Bureau of Indian Standards certification not the only reason behind the proliferation of air purifiers.

The products made by large organised players are too pricey for an average Indian household. That’s something brands are looking to address.

“The much bigger problem that needs to be solved is at the mass and premium end of the market. That’s why we started engineering compact air purifiers that will be suited to Indian room sizes,” Honeywell’s Pillai said.

By next year Honeywell is also looking at local manufacturing. “Last year, our prices points were around Rs 12,000 to Rs 20,000. Today we are at Rs 8,000. Next year we want to manufacture it fully in India, so prices can come down further,” Pillai said.

Once prices fall, markets beyond Delhi, which accounted for roughly 90% of all sales in 2016, can be penetrated, according to executives at large companies said.

Demand has anyway begun to shift over the last two years, as the air gets increasingly toxic in cities like Kanpur, Patna, Bengaluru, Mumbai, and Lucknow. Last year, a report from the World Health Organisation found that 14 of the world’s 15 most polluted cities are in India.

To push greater penetration, brands are pumping money into advertising. “We are working very hard to spread the information that indoor pollution is a year-long problem. While our efforts peak during this time of the year,” said Philips’s Taurani.

While demand for air purifiers is unlikely to settle down anytime soon in an increasingly polluted India, growth is not guaranteed, given how little Indians take this problem seriously.

This article first appeared on Quartz.