How does the EN 71-3 standard issued by the EU differ from other international toy safety standards?

EN 71-3 is a European standard for the safety of toys, specifically targeted towards the migration of certain elements from toys or parts of toys. "Migration" in this context refers to the quantity of a particular substance that can be transferred from the toy into a child under conditions closely resembling those of the human digestive system. These certain elements include but are not limited to antimony, arsenic, barium, cadmium, chromium, lead, mercury, and selenium.

Here’s how EN 71-3 may differ from other international toy safety standards:

1. **Specificity of Substances**: The EN 71-3 standard explicitly lists the maximum migration levels for a specific set of substances. While many international standards cover similar hazards (e.g., mechanical, fire safety), not all detail the chemical hazards in such specificity.

2. **Migration Limits**: EN 71-3 mainly focuses on migration limits, rather than total content. In contrast, some standards, such as the U.S. Consumer Product Safety Improvement Act (CPSIA) lead rules, have stringent total content requirements regardless of migration levels.

3. **European Context**: The various toy safety standards around the world are influenced by their regional contexts. For example, EU regulations including EN 71-3 might be stricter due to historical incidents and a regulatory environment emphasizing precaution. 

4. **Scope of Standards**: Some standards may focus more on physical and mechanical aspects of toy safety (like ASTM F963 in the US), while EN 71-3 is specifically about chemical safety.

5. **Categorization of Toys**: The EN 71-3, apart from defining limits, also categorizes toys based on their likelihood of being placed in the mouth by children. This could influence how a toy is tested and its allowable limits, a level of detailed categorization that might not occur in other standards.

6. **Enforcement and Certification**: Conformity to EN 71-3 is required for toys to receive the CE (Conformité Européene) mark, which signals that they can be sold within the European Economic Area. Other international standards likewise have different enforcement mechanisms and marks or certifications.

It's important to consult the actual text of each standard and possibly acquire professional advice when having to comply with these requirements, as misinterpretation can lead to non-compliance and potential harm to end-users. Moreover, standards may be updated over time, so it's crucial to refer to the most recent versions.