Keep security measures

Until airports can install more sophisticated bomb detection devices, American travelers should be content to limit their carry-on bottles of shampoo and hair gel to 3 ounces.

Authorities enacted the ban on larger bottles nearly a year ago after British police foiled a plot to blow up transatlantic flights using liquid explosives. The ban on all liquids later was revised to allow passengers to board with a small plastic bag containing 3-ounce bottles.

Starting Aug. 4, travelers without infants along will be allowed to carry more breast milk on to planes to accommodate working mothers. And travelers also will be permitted to carry disposable butane lighters and refillable lighters, although torch-style lighters, with hotter flames, still will be barred.

To some, even these loosened regulations may seem like nitpicking. But, until screeners have the use of high-tech X-rays or machines that detect the presence of explosives, the regulations make sense.

Last week, the Transportation Security Administration notified federal air marshals and its own security officers of a possible warm-up by terrorists for a plot to blow up planes. Security officials had made four curious seizures at airports, including items such as wires, switches, pipes or tubes, cell phone components, and dense clay-like substances such as block cheese.

Officials speculate that terrorists might be practicing to carry explosives on to planes and checking to see if screeners will notice. Security officers are advised to look for "ordinary items that look like improved explosive device components."

Ordinary items -- like bottles of shampoo or hair gel.