Which signal word indicates that a product is highly toxic and can kill with low exposure?

The signal word that indicates a product is highly toxic and can cause death or serious harm with minimal exposure is "Danger - Poison" accompanied by the skull and crossbones symbol. This designation is reserved for substances that pose the highest level of risk, indicating that even a small amount can be hazardous.

In understanding signal words, "Caution" is used for products that are of lower toxicity and generally describe products that should be handled safely but do not carry an immediate risk of severe harm. "Warning" indicates a moderate level of toxicity, suggesting that the product can cause harm if ingested, inhaled, or comes into contact with skin, but it is not as severe as the designation used for highly toxic substances. The general "Danger" signal word also signifies high toxicity, but without the specific implication of extreme threat that "Danger - Poison" provides; thus, it covers a broader range of hazardous materials without pinpointing the lethal nature and lower exposure risk.

Therefore, the distinctive labeling of "Danger - Poison" with the skull and crossbones makes it explicitly clear that the product requires the utmost caution due to its potential lethal effects from minimal exposure.