Final answer:
Glass shards, tacks, and hair are examples of physical contaminants, which are tangible objects that can contaminate food or consumer goods and potentially cause harm.
Step-by-step explanation:
Glass shards, tacks, and hair are examples of a type of contaminant known as physical contaminants. These items are tangible objects that can enter food, water, or other consumer goods, and pose a risk because they can lead to injury or illness if ingested or come into contact with the body. Unlike chemical, biological, or radiological contaminants, which include substances like heavy metals or bacteria, physical contaminants do not involve a chemical reaction or multiplication of microorganisms.