What does the symbol for toxic or poisonous substances indicate?

The symbol for toxic or poisonous substances specifically indicates that the materials can cause harm if ingested, inhaled, or come into contact with skin. This warning is crucial for ensuring safety as it alerts individuals to the potential dangers associated with these substances. Recognizing this symbol prompts the need for careful handling, usage of personal protective equipment, and adherence to safety guidelines to prevent accidental exposure or poisoning.

In contrast, the other options describe categories of substances that do not pose the same level of risk as toxic materials. Harmless materials imply safety, while non-toxic cleaning agents suggest they do not produce harmful effects. Flammable liquids indicate fire hazard rather than toxicity. Therefore, the correct interpretation of the toxic symbol is essential for promoting safety and recognizing the inherent dangers of specific substances.