They used to be around, but a few years back importing oats became more difficult - something about very, very high thresholds for pesticide amounts, thresholds that are chemically well-nigh impossible to attain. (Am I too cynical to think that someone who sells oats found a way to eliminate the competition?)
Below are a few links. Key quote I suppose - note how strict Taiwan is!:
Taiwan does not permit residues levels of glyphosate to exceed 0.1 ppm … the maximum level of glyhosate residues currently allowed in foods is 30 ppm in the U.S., 20 ppm in Japan and the European Union, 15 ppm in Canada and 0.1 ppm in Australia.