ASTM D7257-06(2011)

1.1 This test method covers the measurement of the force required to separate (or “shell”) the snap-fitted outer cap from the inner cap of Type IA, IB, or IC child-resistant closures. See Practice D3475.

1.2 This test method is an alternative to Test Method D3481, a manual test procedure.

1.3 This test method does not measure the force required to separate parts of a child-resistant closure system that were originally “screwed-on” instead of “snapped-on” (for example, pull a cap over or through continuous or multi-start threads when the cap was originally screwed on).

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Significance and Use:

This test method of applying force may be used as a standard test to compare the characteristics of a given design of container/child-resistant closure system with a standard or to compare the characteristics of container/child resistant closure systems differing in construction.

It may be used to simulate certain manipulations that may be expected to occur in protocol testing (such as, prying with the teeth, or objects in the room, biting, and pulling with the teeth).

This test may be used to establish performance specifications. Shelling force may vary with cap application torque, bottle design, and other factors. Consequently where precise comparative results are desired, these factors must be carefully controlled.