...

gefahrgutformular/gefahrgutformular.cls

@@ -33,6 +33,7 @@
 \RequirePackage{graphicx,pict2e,picture,eso-pic}
 \RequirePackage[ngerman]{babel}
 \RequirePackage{siunitx-PTB}
+\ifluatex\RequirePackage{luaimageembed}\fi
 
 \let\vl@tempdima=\@ovxx
 \let\vl@tempdimb=\@ovyy
@@ -169,7 +170,6 @@
         \ifx\vl@SignatureGraphic\@empty
           \ifx\vl@SignatureGraphicBaseLXIV\@empty\else
             % https://github.com/csachs/luaimageembed
-            \RequirePackage{luaimageembed}%
             \includegraphicsembedded[height=26bp]{\vl@SignatureGraphicBaseLXIV}%
           \fi
         \else

gefahrgutformular/test-gefahrgutformular.tex

@@ -25,7 +25,7 @@ Pfeiffer-vacuum SAS\\
   \item 6 Lecks; Druck \SI{1.5}{\bar}; UN 1046; Helium \dots
   \item 2 Lecks; Druck \SI{1.5}{\bar}; UN 1046; Wasserstoff \dots 
 }
-\SignatureGraphic{SIG_Ute_Becker.png}
+%\SignatureGraphic{SIG_Ute_Becker.png}
 \SignatureGraphicBaseLXIV{%
 iVBORw0KGgoAAAANSUhEUgAABdoAAAGgCAYAAAC9hNWKAAAWGXpUWHRSYXcgcHJvZmlsZSB0eXBl
 IGV4aWYAAHjarZpnclw5loX/YxW9BLgLsxzYiNnBLL+/g8ySSqrqiuiJYUrM5OMzwDXHAHTnf//n