Dimethyl fumarate (DMF) is the methyl ester of fumaric acid. DMF was initially recognized as a very effective hypoxic cell radiosensitizer - drug that makes tumor cells more sensitive to radiation therapy. It is sometimes also known as a radiation sensitizer or radio-enhancer.. Later, DMF combined with three other fumaric acid esters (FAE) was licensed in Germany as oral therapy for psoriasis.

The precise mechanism of action of dimethyl fumarate is unknown. The compound (and its metabolite, monomethyl fumarate) activates the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway and has been identified as a nicotinic acid receptor agonist in vitro

In a non-medical use, DMF was applied as a biocide in furniture or shoes to prevent growths of mold during storage or transport in a humid climate. However, due to incidences of allergic reactions after skin contact the European Union banned DMF in consumer products since 1998, and since January 2009 the import of products containing DMF was also banned. Dimethyl fumarate has been found to be an allergic sensitizer at very low concentrations, producing eczema that is difficult to treat. Concentrations as low as 1 ppm may produce allergic reactions. The sensitizing risk was brought to public attention by the "poison chair" incident, where Chinese manufacturer Linkwise produced two-seater sofas with dimethyl fumarate sachets inside to inhibit mold while they were in storage or transport. In the United Kingdom, sofas sold by Argos, Land of Leather and Walmsley Furnishing containing the chemical caused over a hundred injuries. Argos withdrew the sofas from stores and contacted buyers to collect those that had been sold — with Land of Leather withdrawing the sofas without notifying buyers and Walmsley saying they had removed the sachets from sofas they sold after the danger came to light. Complaints have been made that dates on the sofas were altered and sofas containing the sachets sold.Land of Leather and Walmsley are facing a ₤10 million class action suit over their reaction to the incident, joining the manufacturer in denying the sofas are connected to their customers' injuries.The danger came to public attention in 2008 when the BBC Watchdog program alerted consumers to the sofas

Formal Chemical Name (IUPAC)
dimethyl fumarate

References

https://en.wikipedia.org/wiki/Dimethyl_fumarate

http://news.bbc.co.uk/1/hi/england/west_midlands/8234760.stm