Latex / Nitrile Gloves Required When Using Chemicals Sign Mandatory Signs Specify that an instruction must be carried out. Symbols (or "pictograms") are depicted in white on a blue circular background. Sign wording, if necessary, is in black lettering on a white background. Mandatory signs comply to AS 1319 regulations. Latex / Nitrile Gloves Required When Using Chemicals Sign Mandatory Signs Specify that an instruction must be carried out. Symbols (or "pictograms") are depicted in white on a blue circular background. Sign wording, if necessary, is in black lettering on a white background. Mandatory signs comply to AS 1319 regulations.