looked at 80 previous studies to find out. The results: Hair dye probably does not generally raise the cancer risk but some very old dyes that used chemicals like 2,4-diaminotoluene and 2,4-diaminoanisole may have indeed been risky. Those chemicals are no longer used in modern dyes. So for younger people, dye probably was not a contributor. For senior citizens that dyed their hair a great deal - it might have contributed to the lymphoma risk.
The debate has raged for decades - does hair dye raise the risk of lymphoma. A