pentachlorobenzene
... that in May 2009, pentachlorobenzene was added to the list of chemical compounds covered by the Stockholm Convention, an international treaty which restricts the production and use of persistent organic pollutants?
... that in May 2009, <b id="mwBw8"><a href="./Pentachlorobenzene" id="mwBxA" rel="mw:WikiLink" title="Pentachlorobenzene">pentachlorobenzene</a></b> was added to the list of chemical compounds covered by the <a href="./Stockholm_Convention_on_Persistent_Organic_Pollutants" id="mwBxE" rel="mw:WikiLink" title="Stockholm Convention on Persistent Organic Pollutants">Stockholm Convention</a>, an international treaty which restricts the production and use of <a href="./Persistent_organic_pollutant" id="mwBxI" rel="mw:WikiLink" title="Persistent organic pollutant">persistent organic pollutants</a>?