Figure 2.

Time Required for Children to Empty Open Control Bottles, Incompletely-closed Control Bottles, and Bottles with Flow Restrictors^a

Abbreviations: FR-bottle, uncapped bottle with a flow restrictor

^a Child testing of control bottles was ended and the bottles were considered empty when the tester noted pauses ≥1 second between drops of test liquid when fully inverted. Weighing of control bottles confirmed removal of ≥88% of test liquid in all cases. Flow restrictor bottles were manually inspected when a child who had been successfully removing test liquid appeared to be unable to remove additional amounts. If a bottle appeared to be empty by manual inspection, testing was ended. Weighing of flow restrictor bottles confirmed removal of ≥88% of test liquid in all cases.

^b Time not recorded for 1 trial with an incompletely-closed control bottle.