Customs agents have seized three gallons of a chemical used to make the date rape drug GHB at Los Angeles International Airport amid a surge in illegal shipments of the intoxicant, authorities said on Wednesday.

Customs and Border Protection officers discovered the three, one-gallon plastic jugs of Gamma-Butyrolactone, or GBL, in a late July shipment from China, labeled as "Propylene Glycol," a spokesman for the agency said.

Tests this week confirmed that the clear liquid was GBL, a key ingredient in the date rape drug GHB, which is known on the street by such names as Everclear, Easy Lay, Georgia Homeboy, Liquid Ecstasy or Salty Water.

It has become popular in recent years at dance clubs and rave parties, CBP spokesman Jaime Ruiz said, and has become known as a date rape drug because in certain doses it can render an unsuspecting victim incapable of resisting advances.

Gamma-Butyrolactone also has legitimate uses in paint thinners and solvents but it's import is regulated by the U.S. Drug Enforcement Administration.

Ruiz said the three gallons of GBL, which have an estimated street value of about $1,400, were being sent to an undisclosed address somewhere in Southern California.

No arrests had been made but Ruiz said customs officials had seen a rise in illegal shipments of the drug and were seeking to alert parents.

"We want parents to be aware that this stuff is coming, we're seeing a bigger volume," Ruiz said. "This release was strategically put out there as a heads up to parents to make sure they know this stuff is out there and it's pretty dangerous."

The effect of GHB is similar to alcohol, causing relaxation, reduced inhibitions and sleepiness, said Sheila Eng, assistant Los Angeles lab director for the CBP.

Large quantities can cause short term amnesia, she said, and an overdose can lead to coma or even death.