The senate is expected to pass legislation today which will ban an entire group of chemicals used to make illegal synthetic drugs in an effort to prevent drugs gangs outwitting the law.

Until now, each new drug has to be put on list of illegal drugs separately. That means manufacturers had to only change one molecule of one of the substances in the drug to make it legal again.

For example, when designer drug 4-MMC was put on the list, it was turned into 3-MMC and when that was banned it became 2-MMC, which is still legal and has practically the same effect as its previous incarnations.

By banning an entire group of psychoactive substances, the government hopes to put an end to this game of cat and mouse.

Police have been lobbying for a change in the law for years, particularly since most of the chemicals are illegal abroad, but traders can freely buy the drugs online in this country.

“It is damaging our reputation and is turning the Netherlands into a free-for-all all for criminal gangs,” drugs portfolio police chief Willem Woelders told broadcaster NOS. This has resulted in threats, attacks, and severe risks to public safety, such as explosions in illegal and unsafe labs, he said.

Not everyone is happy about the new legislation. “It is like firing a cannonball at a mosquito”, Kaj Hollemans from campaign “Normaal over drugs” which tries to destigmatise drug use said. “The group that uses designer drugs is small and they are usually aware of the dangers.”

The new law will ban three groups of substances that mimic the effects of MDMA, cannabis and heroin.

The first group is most prevalent in the Netherlands, and includes 3-MMC, 4-MMC and 3-CMC, said Joris van den Berg, a drugs researcher at the Dutch forensic institute NFI. The second group comprises cannabinoids which are mainly exported abroad. The third group is made up of fentanyl-like substances which are on the list because of their acute danger to life.

Although the new legislation will help, the banned substances can be easily replaced by others, Van den Berg said. “LSD is on the banned list but again, with a bit of tinkering it can be made into a different and legal substance,” Van den Berg said.