Which route of exposure is NOT applicable for the substance?

The correct choice indicates that "Absorption through nails" is not considered a typical route of exposure for substances. In the context of chemical exposure, routes such as ingestion, inhalation, and skin contact are recognized as common ways that individuals can be affected by hazardous materials.

Ingestion refers to swallowing substances, which can lead to systemic effects if the ingested material is toxic. Inhalation involves breathing in substances, which can directly impact the respiratory system and enter the bloodstream quickly, leading to immediate effects. Skin contact encompasses scenarios where a substance comes into contact with the skin, potentially causing irritation, burns, or systemic absorption, depending on the chemical properties of the material.

While nails are part of the skin, absorption through nails is generally not considered an effective or significant route for substance exposure. The keratin in nails acts as a barrier, making it difficult for many substances to penetrate. Therefore, it is not listed among the primary or recognized exposure routes for chemicals, setting it apart from ingestion, inhalation, and skin contact. This distinction is important for understanding safety protocols and exposure risk evaluations in various industrial settings.