EN 71-3 is a standard that deals with the migration (ie leakage) of certain elements from toys or toy materials. Children, especially at a young age, may put toys in their mouths. Therefore, there is a risk of potentially toxic elements leaching from these toys. EN 71-3 defines the amount of such elements that can leak from toys and specifies that these leaks must not exceed certain limits.

**The main focuses of EN 71-3 are:**

1. **Specific Elements**: The standard restricts leaching amounts of a number of potentially hazardous elements. These elements include Antimony (Sb), Arsenic (As), Barium (Ba), Cadmium (Cd), Chromium (Cr), Lead (Pb), Mercury (Hg) and some other elements.

2. **Test Matrices**: EN 71-3 defines different test matrices according to different materials of toys. For example, test procedures and limit values may vary depending on whether it is dry, moist or aqueous material.

3. **Test Methods**:
    - Toy materials are kept in an acidic solution (usually hydrochloric acid) for a certain period of time. This mimics leaking stomach acid.
    - Then, it is determined which elements and in what quantity are leaked in this solution.
   
4. **Limitations**: The standard defines limit values for the amount of leaching for each specific element. These limits are set based on scientific data and the need to protect children's health.

5. **Field of Application**: EN 71-3 applies to both toys and any product in direct contact with toys. For example, materials such as paints, adhesives, printing inks are considered within this scope.

Compliance with the EN 71-3 standard ensures that children are assured of limited amounts of potentially toxic elements to which they may be exposed when using these toys. Manufacturers should periodically test and verify the conformity of toys to this standard. This both ensures the safety of children and helps the manufacturer avoid potential regulatory issues.