Alkanes can be chlorinated or brominated by treatment with chlorine or bromine in the presence of visible or uv light .
烷在可见光或紫外光的照射下，用氯或溴处理能氯化或溴化。
The article that kavanagh read in scientific american said that the ingredient has been banned in japan and europe , and that bromine is cited in chemical company patents as a flame retardant .
