Photo/Illutration Liquid marijuana, contained in a cartridge, is designed to be inhaled with a heating instrument. (Provided by the Narcotics Control Department of the Kanto-Shinetsu Regional Bureau of Health and Welfare)

Police have revised drug identification methods to crack down on new and elusive forms of marijuana, but experts warn the system still allows narcotics makers to stay a step ahead of the law.

One reason for the change was the spreading use of liquid marijuana, which is designed to be inhaled like an e-cigarette.

The previous method for identifying marijuana products relied on observing samples with a microscope and confirming the presence of bristles, or fine hairs, that are characteristic of the cannabis plant.

These bristles often do not show up in liquid marijuana, and some suspects escaped prosecution because of this loophole.

Wax cannabis products have also rapidly circulated in increasing quantities in recent years.

Both liquid and wax marijuana contain concentrated forms of tetrahydrocannabinol (THC), a hallucinogen, and produce a stronger effect than the dried form, sources said.

Marijuana is called a “gateway drug” because it is often the first narcotic experienced by people and can lead to the use of stronger drugs.

Marijuana cases characteristically involve suspects in their 20s and 30s, as well as a growing number of minors.

Figures from the Finance Ministry’s Customs and Tariff Bureau show that action was taken at customs houses across the nation in 131 cases of illegal cannabis products in non-plant form in 2019, more than double the corresponding number five years earlier.

When police investigate narcotics cases, they test the seized drugs to prove they are in fact illegal.

However, the bristles often disappear in the process of extracting THC for the non-plant products. The Cannabis Control Law could not be applied to such products under the traditional testing method because the hairs were not found.

In response to the difficulties faced by investigators, the National Police Agency revised its cannabis testing method and issued a corresponding notice to police departments across Japan in August 2019. The NPA instructed them to adopt the new method from the following month.

The health ministry’s narcotics control departments introduced the new testing method earlier.

The new procedure recognizes an illegal cannabis product if, for example, it contains a certain concentration of THC as well as a characteristic component.

In one case, the Tokyo District Public Prosecutors Office indicted a man in his 40s on charges of cannabis possession, including in liquid form. The Tokyo District Court found the suspect guilty.

“Attention will be focused in the future on whether that sort of judicial decision will become the norm,” one investigator said.

However, some types of cannabis products have emerged that can elude such classification even with the new method, sources said.

Another investigator said the new cannabis products are reminiscent of borderline drugs of the past. The drug makers stayed ahead of law enforcement by partially changing the chemical structures of their products to avoid falling under the “illegal” definition.

“Things are only going around in circles,” the investigator said.

Masahiko Funada, chief of the Section of Addictive Drugs Research at the National Center of Neurology and Psychiatry, noted the health dangers of liquid marijuana and other non-plant products, which typically have THC concentrations of 60 to 80 percent, compared with 10 percent or so in dried cannabis.

“Regulators should be allowed to crack down on drugs on the basis of their THC content, be they cannabis or not,” Funada said.

Satoshi Numazawa, a professor of toxicology at Showa University’s School of Pharmacy, also said the current regulation system is ineffective.

“Existing law fails to cope with the current situation because new types of cannabis products are popping up one after another,” he said. “The regulation system probably needs a drastic change.”

Numazawa said any drug containing THC should be called illegal.

“There should be a single law for blanket regulations on all sorts of drugs, like in Western countries, instead of having separate laws for separate types of drugs, like the Cannabis Control Law for cannabis alone,” he said.

(This article was written by Yuko Kawasaki and Chihaya Inagaki.)