Walking into the men’s restroom at the Shuibei International Center in Shenzhen’s Luohu District, you’re greeted by a sign that reads “Smoking makes the glass transparent”. After several failed attempts to discourage people from smoking in its indoor bathrooms, the Chinese shopping center decided to implement special doors that become transparent when smoke is detected.
A spokesperson for the shopping center told journalists that the company had previously imposed fines on people caught smoking in the restroom and even banned some of them for a period of time, so it decided to discourage the habit by threatening to expose offenders.

“Resist the urge to smoke, unless you want to become internet famous!” another sign in the Shuibei International Center bathroom reads. The idea is to scare possible offenders that they could be photographed or recorded at their most vulnerable, with the footage then shared online.
The new toilet doors feature a rectangular glass window containing a special silver halide compound and are usually frosted for privacy. However, when a sensor connected to the door detects cigarette smoke and heat in the cubicle, the molecules react and instantly change from frosted to clear glass. Then, as that wasn’t bad enough, a loud warning message is broadcast in the restroom:

“In accordance with the Secondhand Smoke Prevention Ordinance, this is a public place where smoking is prohibited. For your own health and the health of others, please do not smoke here.”
The initiative has gone viral on Chinese social media, sparking a heated debate between those who see it as an effective deterrent against bathroom smoking, which is apparently very common in the Asian country, and those worried about their privacy.

“It seems we finally have an effective way to combat smoking,” one person commented online.
“Smoking in men’s restrooms in China is practically ubiquitous. It’s not uncommon for people to choke the moment they enter. I think this is a great idea,” someone else wrote.
On the other hand, people wondered what would happen if the system somehow malfunctioned or was somehow manipulated.

“If I blow smoke under the door or into the gap from outside, will it still be transparent?” one person asked, while another asked if the system reacted in the same way to perfume or other volatile compounds.
For now, the new bathroom doors are in the trial period, but if the response from the public isn’t particularly negative, they will become a permanent fixture at the Shenzen shopping center.