Gadgets: Don't Breathe Easy

Would you decide to drink and drive based on the results of a $1.49 test? If you would, the makers of the Guardian Angel Personal Alcohol Test are ready to help. Available in drug and grocery stores nationally, the product lets you test your blood alcohol content by licking a chemically treated paper strip (guardianangel.com). Police in several states even gave the strips to motorists over Labor Day weekend.

To assess the Guardian Angel, as well as a $50 purse-size breathalyzer (the PSI BT5500) from Sharper Image, NEWSWEEK enlisted the help of a government official. He brought along the Alcotest 7410 Plus, a $2,000 machine used by police. Three NEWSWEEK volunteers drank for two hours, comparing readings on all three test systems. Hardly scientific, but here's our general advice:

It's an Estimate: You probably shouldn't base a decision to drive solely on the results. (The manufacturers say it's never smart to drink and drive; Tip Sheet agrees.) However, after moderate consumption, the two lower-priced tests approximated the Alcotest 7410 results.

Follow the Directions: The saliva strips call for a 10-minute wait after drinking; the $50 unit suggests a 30-minute pause. Ignoring the instructions skewed the results.

Don't Judge Yourself: The more the volunteers drank, the more difficulty they had performing and interpreting the tests. Let someone sober read the results.

Lower Limits: None of our test subjects say they'd feel safe driving with a blood alcohol content remotely near the legal limit--usually 0.08. The bottom line: trust a designated driver before any gadget.