Why is there always a gap under the door of a public toilet? The reason is...

During the May Day holiday, did you join the huge crowds of tourists?

No matter where your destination is, I believe there is one place you will definitely go to - a public toilet.

Copyright image, no permission to reprint

You may find that public toilets everywhere seem to be very similar in two aspects: first, the door panels of toilet cubicles are not fully enclosed, but there is a gap between them and the ground. Second, in front of public toilets in many tourist attractions, women always queue up in long lines, while men can "come and go freely".

How do we achieve "national consistency" in these two points? Let's talk about these two things today.

01

Gap under toilet door

First of all, let’s talk about why toilet door panels across the country are not fully enclosed. Is it really to make it easier to pass paper to people?

The answer to this question is very simple. It is actually a mandatory rule that there must be a certain space left behind the toilet door.

Our country's "Urban Public Toilet Design Standards" (CJJ14-2016) clearly stipulates that a gap must be left under the door panels and partitions of independent unit rooms of public toilets, and the gap size must be greater than 10 cm.

Copyright image, no permission to reprint

But why set such an interval?

There is no clear reason given in the "Urban Public Toilet Design Standards", but we can still find possible reasons from other materials.

Requirements for cubicle doors and partitions in the Urban Public Toilet Design Standards

In addition to our country, some countries also have requirements for the height of toilet door panels, such as the United States.

The Americans with Disabilities Act stipulates that there must be a 9-inch (about 23 cm) gap between the independent unit door of a public restroom and the ground, which is much higher than the height in China.

The reason for this regulation is to allow disabled people to have space to move their assistive devices (such as wheelchairs) freely.

Image source: Internet

But the gap between door panels in China is smaller than this. In addition, in public toilets near shopping malls, stations, airports, parks and streets with large traffic, it is mandatory to set up special toilets for the disabled, so this reason is not applicable in China.

But in addition to the Americans with Disabilities Act, the American Public Restroom Association also gave an explanation for the phenomenon that "door panels do not directly reach the ground", which can be summarized into the following two reasons:

1. Cleaning requirements

Compared with fully enclosed partitions and door panels, door panels with gaps are more convenient for cleaning staff to clean the floor. After all, cleaning staff can easily put the mop under the door panel to clean, and it is not easy to have dead corners to clean. This is the original intention of setting the door panel interval.

But in actual use, people found that such door panels can also bring safety benefits.

2. Security requirements

The American Public Restroom Association also mentioned in its explanation that such a non-fully enclosed door panel allows people to promptly discover the situation in the adjacent compartment.

If there are bad guys doing bad things here (such as robbery or unfair transactions), people nearby can quickly call the police.

In addition, bad guys may consider that the compartment is not so airtight and give up doing bad things here, so this design can play a certain role in reducing the crime rate.

Also, if someone secretly smokes in a non-smoking bathroom, the smell of smoke will quickly drift out from the non-fully enclosed cubicle, and the management can discover and stop it in time.

Copyright image, no permission to reprint

In addition, there is another safety benefit to toilet cubicles that are not fully enclosed. Although this benefit is not mentioned in the explanation of the American Public Toilet Association, it is very important - the gap under the toilet cubicle may save lives.

People can see through the gaps in the compartments whether someone has fainted inside and rescue the fainted person in time.

Such things do happen, and they happen many times every year. For example, in 2022, a girl fainted in a public toilet in Songyang Service Area, Lishui City, Zhejiang Province. It was because someone saw a foot sticking out of the gap under the toilet cubicle that the girl was rescued in time.

If the toilet cubicle is completely enclosed, it may take a long time for the person inside to be discovered after fainting, which may miss the best time for rescue and lead to tragedy.

02

Gaps between door panels and partitions

There are other benefits

1. Ventilation volume requirements

For example, the "Urban Public Toilet Design Standard" CJJ14-2016 has clear regulations on the ventilation volume of each squatting, sitting and standing position in public toilets.

If it is a fully enclosed compartment, the requirements for the layout of ventilation equipment will be higher, so the gap under the door panel can also solve part of the ventilation needs.

2. Durability requirements

In addition, the door panels are not tightly fitted to the ground, which saves materials during construction and is less prone to problems.

If it is really fully enclosed, the size of the door panel cannot have the slightest error, otherwise it may rub against the ground and cause damage.

Having said that, such a door panel with a gap can really provide hope for those who forget to bring toilet paper when going to the toilet. After all, someone can hand you the paper, and you don’t have to go through the embarrassment of looking at each other.

03

Women's toilet queue problem

Why are there long queues in women's toilets in many places across the country? This is actually related to the 2005 edition of the "Urban Public Toilet Design Standards".

In the previous standards, the ratio of male and female toilets was set at 1:1 to 1:1.5.

Moreover, this ratio only refers to the proportion of squatting positions, and men's toilets often also have standing positions (that is, urinals), so there may be more toilets in men's toilets than in women's toilets.

Copyright image, no permission to reprint

Considering that the average time men spend in the toilet is shorter than that of women, this setting is obviously unreasonable.

Fortunately, the 2016 edition of the "Urban Public Toilet Design Standards" adjusted the ratio of male and female toilets in public toilets: "In places with concentrated traffic, the ratio of female toilets to male toilets shall not be less than 2:1."

More importantly, the men's toilets here include not only squatting and sitting seats, but also standing seats for urinals.

Under this standard, in new public toilets built after January 1, 2016, women's toilets will have more toilet seats than men's toilets and will be larger in area.

The 2016 edition of the Urban Public Toilet Design Standard stipulates the number of male and female toilets in shopping malls.

Of course, many public toilets in scenic spots and shopping malls were built before 2016, so there is still an unreasonable ratio. But I believe that with the increase of new public toilets, the problem of long queues for women to use the toilet will be gradually solved.

References:

[1] Urban Public Toilet Design Standard (CJJ14-2016)

[2] https://www.ada.gov/resources/title-iii-manual/#iii-40000-specific-requirements

[3] https://americanrestroom.org/restroom-security/

Produced by | Science Popularization China

Author｜Science Scraps Popular Science Team

Review | Cheng Shikun, Associate Professor of Environmental Science and Engineering, University of Science and Technology Beijing

The cover image and the images in this article are from the copyright library

Reproduction of image content is not authorized