Which category of the synthetic detergents is used in toothpaste ?

Explanation

**Step-by-Step Solution:**

1. **Understanding Synthetic Detergents:**
Synthetic detergents are classified into four main categories: anionic, cationic, nonionic, and amphoteric detergents. Each type has distinct properties and uses.

2. **Identifying the Category Used in Toothpaste:**
In toothpaste, the category of synthetic detergents primarily used is **anionic detergents**.

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