Under pressure from Democrats in Congress, Target Corp. has asked the U.S. Department of Agriculture to let it attach warning labels to meat it sells that has been treated with carbon monoxide to make it appear fresher than it is. The proposed label reads: “CONSUMER NOTICE: Carbon monoxide has been used to preserve the color of this product. Do not rely on color or the ‘use or freeze by’ date alone to judge the freshness of the product. For best results please follow the Safe Handling Instructions.” In the wake of recent food-safety scares, other companies such as Safeway and Tyson Foods have vowed not to sell carbon monoxide-treated meat. But Target’s move, while likely better than nothing, would not prohibit such meat from being sold in its stores. Congressional Democrats are also pressuring other big companies to stop selling CO-treated meat or label it.