TBHQ
<p ><b><i>tert</i>-Butylhydroquinone</b> (<b>TBHQ</b>, <b>tertiary butylhydroquinone</b>) is an <a href="http://en.wikipedia.org/wiki/Aromatic" title="Aromatic" class="mw-redirect" >aromatic</a> <a href="http://en.wikipedia.org/wiki/Organic_compound" title="Organic compound" >organic compound</a> which is a type of<a href="http://en.wikipedia.org/wiki/Phenols" title="Phenols" >phenol</a>. It is a derivative of <a href="http://en.wikipedia.org/wiki/Hydroquinone" title="Hydroquinone" >hydroquinone</a>, substituted with <i>tert</i>-<a href="http://en.wikipedia.org/wiki/Butyl" title="Butyl" >butyl</a> group.</p>
<h2 >Applications</h2>
<p >TBHQ is a highly effective <a href="http://en.wikipedia.org/wiki/Antioxidant" title="Antioxidant" >antioxidant</a>.<sup id="cite_ref-OBrien_0-0" class="reference" ><a href="http://en.wikipedia.org/wiki/TBHQ#cite_note-OBrien-0" >[1]</a></sup> In foods, it is used as a <a href="http://en.wikipedia.org/wiki/Preservative" title="Preservative" >preservative</a> for unsaturated <a href="http://en.wikipedia.org/wiki/Vegetable_oil" title="Vegetable oil" class="mw-redirect" >vegetable oils</a> and many edible animal fats.<sup id="cite_ref-1" class="reference" ><a href="http://en.wikipedia.org/wiki/TBHQ#cite_note-1" >[2]</a></sup> It does not cause discoloration even in the presence of iron, and does not change flavor or odor of the material to which it is added.<sup id="cite_ref-OBrien_0-1" class="reference" ><a href="http://en.wikipedia.org/wiki/TBHQ#cite_note-OBrien-0" >[1]</a></sup> </p>
<p>
It can be combined with other preservatives such as <a href="http://en.wikipedia.org/wiki/Butylated_hydroxyanisole" title="Butylated hydroxyanisole" >butylated hydroxyanisole</a> (BHA). As a <a href="http://en.wikipedia.org/wiki/Food_additive" title="Food additive" >food additive</a>, its <a href="http://en.wikipedia.org/wiki/E_number" title="E number" >E number</a> is <b>E319</b>. It is added to a wide range of foods, with the highest limit (1000 mg/kg) permitted for frozen fish and fish products. Its primary advantage is enhancing storage life.</p>
<p>
It is used industrially as a <a href="http://en.wikipedia.org/wiki/Stabilizer_(chemistry)" title="Stabilizer (chemistry)" >stabilizer</a> to inhibit autopolymerization of <a href="http://en.wikipedia.org/wiki/Organic_peroxide" title="Organic peroxide" >organic peroxides</a>. It is also used as a corrosion inhibitor in biodiesel.<sup id="cite_ref-Almeida_2-0" class="reference" ><a href="http://en.wikipedia.org/wiki/TBHQ#cite_note-Almeida-2" >[3]</a></sup> In perfumery, it is used as a fixative to lower the evaporation rate and improve stability. It is also added to <a href="http://en.wikipedia.org/wiki/Varnish" title="Varnish" >varnishes</a>, <a href="http://en.wikipedia.org/wiki/Lacquer" title="Lacquer" >lacquers</a>, <a href="http://en.wikipedia.org/wiki/Resin" title="Resin" >resins</a>, and oil field additives.</p>