三类工业用地是指对居住和公共设施等环境有严重干扰和污染的工业用地。

如采掘工业、冶金工业、大中型机械制造工业、化学工业、造纸工业、制革工业、建材工业等

用地。英文翻译为

Should be "third type land for industrial usage".

But foreigners will never understand. You need toadd remarks to explain the areas it is different from the first and second types of land...Translation is very difficult. Another example is "十一五计划". But use " National Plan 2006 - 2010" instead of "the Eleventh Five - year Plan".