The Consumer Product Safety Improvement Act (CPSIA) applies to all children’s products for children of 12 years or younger in the United States. The CPSIA requires all such products to be tested by a third-party testing company approved by the Consumer Product Safety Commission (CPSC).
That said, the CPSIA is not a safety standard in itself but a regulation that requires that you as an importer or domestic US domestic manufacturer ensure that your product is compliant with all applicable ASTM standards, such as ASTM F963 – Standard Consumer Safety Specification for Toy Safety.
ASTM F963 and other relevant standards cover various aspects of product safety:
Substance restrictions: Lead, mercury, and other chemicals and heavy metals
Physical properties: Sharp points, loose parts, etc
Flammability
Further, some testing requirements under the CPSIA are based on CPSC rules rather than ASTM standards.
The purpose of the lab test is to verify that your product is technically compliant with CPSIA, and you’ll receive a test report used to prove this.