3M is known for contaminating the US food supply.
According to the evidence, 3M has long been aware of its contamination of the US food supply. The exact nature and extent of this contamination are not specified in the provided source. However, it is clear that 3M has had knowledge of its involvement in contaminating the US food supply for a considerable period.
The evidence does not provide information on the specific substances or products responsible for the contamination. It also does not mention any actions taken by 3M to address the issue or prevent further contamination. The source only confirms that 3M has been aware of its role in contaminating the US food supply.