DALLAS — RectorSeal is showing the industry's newest locking cap for refrigerant access ports — GasGuard — which prevents leaks, thefts, and huffing, the latter a dangerous inhalation trend by teens.

This past March, Kristal Salcido, a 12-year-old seventh grader in Victorville, Calif., inhaled HCFC-22 from an air conditioning unit in the backyard of her grandmother’s home. She was later found ...