The list of rules at a newly opened apartment building on the outskirts of Zurich includes no smoking, no perfume, no mobile use and so on.
For a reason: the structure has been purpose built for people who say exposure to everyday products like perfume, hand lotion or wireless devices make them so sick they cannot function.
"I have been suffering since I was a child. This will really move my life in another direction," said Christian Schifferle, the 59-year-old head of the Healthy Life and Living Foundation (www.stiftung-glw.com), the prime driver behind the project.
Schifferle and the other residents suffer from Multiple Chemical Sensitivity (MCS), a chronic condition not broadly recognised by the medical community. Those afflicted, however, believe it is sparked by low-level exposure to chemicals in things such as cigarette smoke, pesticides, scented products and paint fumes.
Twelve of the 15 apartments in the earth-coloured building in a remote part of Leimbach, on the outskirts of Switzerland's largest city, have already been rented since it opened in December.
Many occupants also suffer from electromagnetic hypersensitivity, in which electrical circuits and radiation from wireless equipment make them equally ill.
"It makes me weak, anxious, I can't breath, my lungs hurt, and I get dizzy," says Schifferle, who suffers from both conditions.
While living in the building will not cure Schifferle or others, it aims to make daily lives more comfortable for people whose conditions have often left them isolated and unable to hold jobs.
- 'Only half alive' -
Schifferle, who first felt sick from the fumes in his parents' furniture factory when he was three or four, has lived most of his adult life in a trailer in the pristine Swiss Alps.
It was not until he was 35 and stumbled across an American book on MCS that he realised he was not alone, but it was another decade before he found a doctor who took him seriously.
"All my life it has been like I was only half alive," he said.
The new building is the first of its kind in Europe, according to officials in Zurich who decided to play a pioneering role in helping people with what they called "a very harmful problem".
They estimate about 5,000 people in Switzerland alone suffer from MCS.
The city made available the land and provided interest-free loans to help finance the 6.1-million Swiss-franc ($6.9-million, 5.1-million-euro) project.
"We wanted to help these people to have a calm home where they hopefully will be less sick," said Zurich housing office spokeswoman Lydia Trueb.
With a mask covering his nose and mouth, Schifferle proudly shows off the 0.0 reading on a handheld electricity-measuring instrument with a triangular, green antenna.
"This room is very good, because we have almost no electricity," he said, nodding around a large common area equipped with a big carbon filter to purify the air.
Anyone entering the building is expected to switch off their mobile phones, which in any case do not function inside. But there are landlines for telephone and Internet communication in the building.
Near the entrance, the only cleaning and personal hygiene products residents are allowed to use in the building are on prominent display.
- Only isolation helps -
"Avoiding the environmental burdens is really the only thing that helps most of these patients," said John van Limburg Stirum, an internist specialised in environmental medicine who has treated Schifferle and other MCS patients at the Seegarten Klinik near Zurich.
"They have to find shelter somewhere where there are no antennas, no radiation from cell phones, which is getting more and more difficult," said Stirum.
The condition is difficult to pin down, and sufferers are often dismissed as hypochondriacs.
But a growing body of research suggests an initial chemical exposure can spark an "allergic reaction" in some people when they later confront even very low levels of a range of chemicals.
"These patients are really suffering," said Stirum, who is urging medical recognition of the condition.
The Zurich building was constructed with special materials, by purpose-trained builders banned from smoking or using scented products like cologne as they worked. It has a ventilation system aimed at sucking out all odours.
"I think a good example for the whole thing is the plaster on the wall," said architect Andreas Zimmermann, who designed it.
"It doesn't smell, and that is very important for these people," he added, saying he searched for months for a completely odourless plaster.
The floor plan is layered like an onion "so that the deeper you enter the apartment, the cleaner the rooms get," he said.
The building's most "contaminated" parts are the common areas, main hallway, stairwell and elevator in the centre.
From there, residents enter their apartments, moving through a hallway where they can remove "polluted" clothing, the bathroom and kitchen or other technically equipped rooms, before getting to the "cleanest" rooms: the living room and bedroom.
A special "net" has also been built into the facade and roof to protect inhabitants from electromagnetic or electrostatic waves or fields, Zimmermann said.
Despite all the efforts, Schifferle still only spends a few days a week in his new apartment. More ventilation is needed, he said, until all traces and scents of the builders are gone.