Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 90-05-1, Whether you call it Guaiacol, 2-Methoxyphenol , Methyl Catechol or Pyrocatechol Monomethyl Ether you can be assured the Guaiacol products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.