One of the main causes of death was poisoning from cyanide and other toxic gases released by the burning of plastic and polyurethane foam used in the construction of club interiors. Taking into account the number of deaths, this was the largest fire in post-Soviet Russia.On 27 January 2013, a fire at the Kiss nightclub in the city of Santa Maria, in the south of Brazil, caused the poisoning of hundreds of young people by cyanide released by the combustion of soundproofing foam made with polyurethane. By March 2013, 245 fatalities were confirmed. Gas chambers
In early 1942, Zyklon B, which contains hydrogen cyanide, emerged as the preferred killing tool of Nazi Germany for use in extermination camps during the Holocaust. The chemical was used to murder roughly one million people in gas chambers installed in extermination camps at Auschwitz-Birkenau, Majdanek, and elsewhere. Most of the people who were murdered were Jews, and by far the majority of these murders took place at Auschwitz. Zyklon B was supplied to concentration camps at Mauthausen, Dachau, and Buchenwald by the distributor Heli, and to Auschwitz and Majdanek by Testa. Camps also occasionally bought Zyklon B directly from the manufacturers. Of the 729 tonnes of Zyklon B sold in Germany in 1942–44, 56 tonnes (about eight percent of domestic sales) were sold to concentration camps. Auschwitz received 23.8 tonnes, of which six tonnes were used for fumigation. The remainder was used in the gas chambers or lost to spoilage (the product had a stated shelf life of only three months).
where 
  
    
      
        
          δ
          
            i
            ,
            j
          
        
      
    
    {\displaystyle \delta _{i,j}}
   denotes the Kronecker delta. The physical interpretation of the various terms in the above master equation is straight forward: the terms on the first line describe the growth of fibrils via monomer addition with rate constant 
  
    
      
        
          k
          
            +
          
        
      
    
    {\displaystyle k_{+}}
   (elongation). The terms on the second line describe monomer dissociation, i.e. the inverse process of elongation.