Introduction

Perchloroethylene (aka tetrachloroethylene or PERC) is the main chemical found in products used for dry cleaning worldwide. It acts as a solvent to remove stains from all types of fabrics, since it is an excellent solvent for organic materials. It is volatile, highly stable and non-flammable, reasons for which it is so widely used in this industry. The big selling point of this chemical is that it is quite effective and quite cheap, which means that almost all dry cleaners throughout the globe use it daily. The problem is that PERC is quite toxic, both for humans and the environment. Because of all these reasons, the French government has set up to 2022 the complete banning of PERC from dry cleaning establishments situated close to residential areas. Similar laws had been already passed in Denmark and the USA.

Impact of PERC in Paris' dry cleaners

We interviewed face-to-face all dry cleaners in Paris with the aim of understanding how they would deal with the interdiction of this chemical, as well as assess their level of awareness of the dangers of PERC. We also aimed to understand what were their needs, to try to design a product that would help make their daily life easier.

Our survey (original questionnaire in French or translated version in English) allowed us to create a better suiting product, but it also allowed us to assess the level of awareness of the dry cleaners regarding the dangers of using PERC. The interesting thing about Paris is that the city is divided into 20 neighborhoods, the 20 arrondissements. This division is very interesting for our study because it allows us to make not only a statistical analysis of our data, but also a socio-economical one based on the differences in styles of living in each arrondissement.

250 dry-cleaners and hundreds of kilometres walked after, we got to know which are the most difficult stains to remove and which are the most problematic fabrics.
We also got to know their personal experiences on the use of PERC and the impact that the compulsory change would have on their business. We learnt that the already existing alternatives to PERC are not efficient enough.
Most of the dry cleaners expressed their concern over their business, being afraid that the new methodologies would result in a decrease of the quality of their services. Using the existing alternative to PERC means that it takes longer to remove the stains than it used to take when they used PERC. It also means that for the most difficult stains they need to use pre-washing products to be able to efficiently get rid of the stains.
We learnt that, among the most difficult stains to remove, red wine is a particularly difficult one to get rid off. This type of stains is especially difficult to remove without a trace on white fabrics, since it has very strong pigments. We therefore decided to focus on developing a pre-washing product for getting rid of the verrry Frrrrench red wine stains.

Results

Figure 1: Reported PERC use per arrondissement and observed existing correlations. All data obtained from analysis of the answers to the questionnaire. Original set of data not displayed publicly to preserve the anonymity of the dry cleaners.

On the use of PERC in Paris

The first question we wanted to answer with our questionnaire was the one of how widely spread was the use of PERC in Paris. Our data shows that half the dry cleaners in Paris still use PERC as a solvent in their dry-cleaning facilities (figure 1B), which means that in the followup to 2022, time when the chemical will be prohibited in France, half of the dry-cleaners of Paris will have to make the investment of updating their facilities.
Although we do not have numbers for it because we did not originally include the question in our questionnaire, we found out that many of the dry cleaners that do not use PERC had changed to the alternatives in the previous 5 years.

Looking at figure 1A, we can see that the distribution of the use of PERC in Paris is not homogeneous, with some arrondissements using it much more than others. The 12th and 13th arrondissements were the ones in which the use of PERC was still more prominent, and the north arrondissements, the 17th, 18th, 19th and 20th were the ones in which PERC was most seldom used.
We analysed the socio-economic characteristics of those arrondissements, trying to find some correlation that would help us explain the differences on the use of the chemical. We expected that on the "richest" arrondissements the use of alternatives would be more frequent. We based this hypothesis on the thought that businesses that were located in expensive arrondissements would be able to support the monetary effort that changing all the infrastructures to adapt the dry-cleaners to the new products brings easier than those located in poorer arrondissements. Nonetheless, a correlation between the mean income and the use of PERC was not found. We hypothesised that this might be due to the fact that the French Government has made the effort to support monetaryly the dry cleaners in their change, and thanks to this help, the economical differences between arrondissements are diluted.
We also expected to see a correlation between the awareness of the population that inhabited the arrondissement and the use of PERC. We hypothesised that those arrondissements in which their inhabitants had easier access to high education would be more sensibilised to the dangers of using the chemical, and would therefore pressure their local dry-cleaners to change to the alternatives. Nonetheless, once again, our original premise was completely wrong, since no correlation between white workers and use of PERC was found.
The one correlation that we were able to find was that existing between the use of PERC and the percentage of immigrant population. Those with a higher percentage of immigrant population displayed the lowest values of PERC use. Once we observed this correlation we realised that we had been looking at the data with the wrong perspective. Paris is traditionally a city with a high percentage of immigrant population, and the different populations are well distributed throughout the 20 arrondissements. Nonetheless, the immigrant population is higher in the north districts, which are also the poorer ones. Something that could explain the correlation observed between immigrant population and PERC use is that the people that live in the 17th, 18th, 19th and 20th might both live and work in dry cleaners in these arrondissements. Therefore, a stronger concern would exist on those dry cleaners, since the effects on health of using PERC would be more strongly felt by those both living and working close to PERC-using facilities. A second explanation could also be that the French Government helps more those who most need it, and would therefore have begun helping the dry cleaners in those arrondissements first. A third explanation could also be that the 17th, 18th, 19th and 20th arrondissements have seen a increase in population in the last decades. The new population living there could have started new business, choosing to use the alternatives directly, whereas in the older arrondissements, with long-stablished dry-cleaning facilities, the change would be slower.

Attributions

The Human Practices were designed by the entire team with the help of our advisors. Face-to-face interviews were carried out by Alicia, Allison, Antoine V. and Sébastien (due to the fact that speaking french was necessary to perform them). A big thank you to our advisors Jake and Jason for helping us analyse the results.

References

• The list of the dry cleaners existing in Paris was obtained in the Yellow Pages (Pages Jaunes)
• The statistics for each Arrondissement were obtained in the Mairie de Paris and in the Institut National de la Statistique et des Etudes Economiques