Chemicals covered by the Stockholm Convention are persistent organic pollutants that are banned or tightly restricted, and precursor chemicals are ordinary industrial substances that can be diverted to make drugs or weapons. Both groups need extra checks before you order from India.
The two regimes work differently. The Stockholm Convention is a treaty, implemented through national and regional law. Precursor controls come from separate drug and chemical-weapons conventions, and often apply to common solvents and reagents you would not expect to be controlled.
What does the Stockholm Convention cover?
The Convention lists persistent organic pollutants in annexes. Annex A substances are to be eliminated, Annex B are restricted, and Annex C covers unintentional releases. The list has grown through amendments agreed by the Conference of the Parties, so always check the current annexes on the Convention's website rather than an older list.
In the EU, the Convention is implemented through the POPs Regulation (EU) 2019/1021, which bans or restricts manufacture, placing on the market and use, with low-concentration limits for contaminants. Other markets have their own implementing laws. A product that is legal to make in India for one use may be unlawful to import into your country.
Before ordering, check your product's CAS number against the current annexes, and ask the supplier whether any POP could be present as an impurity. Our guide on agrochemicals banned in the EU but exported from India and the one on the Rotterdam Convention show how related treaties affect exports.
What are precursor chemicals?
Precursors are chemicals that can be used to make illegal drugs. The UN 1988 Convention lists them in tables, and the list includes widely used substances such as acetic anhydride, potassium permanganate, acetone and toluene. Chemical-weapons precursors are controlled separately under the Chemical Weapons Convention schedules.
Controls then apply at national level. In the EU, drug precursors are governed by Regulations (EC) 273/2004 and (EC) 111/2005, which set licensing or registration for operators and customs controls on imports and exports, depending on the category. The United States controls many of the same chemicals through its own listing system. Which substances count, and at what concentration, is set by each jurisdiction.
What happens on the Indian side?
Indian exporters of scheduled precursors need authorisations from the relevant authorities, and the Narcotics Control Bureau oversees the drug-precursor side. Some chemicals also fall under India's SCOMET list of dual-use goods, which needs a separate export licence. See sanctions and SCOMET controls on Indian chemical exports for how that list works.
A manufacturer that quotes you a controlled chemical without mentioning any licence is either unaware of the rules or planning to skip them. Both are reasons to walk away.
What should you check before you order?
- Look up the CAS number in your own country's precursor and POP lists, and in the current Stockholm annexes.
- Ask your customs broker whether the product needs an import licence, a registration or a customer declaration.
- Ask the supplier which export permission it holds and for a copy of the authorisation before shipping.
- Confirm the end use and the end customer in writing, since regulators may ask for both.
How we help
We cannot give legal advice, but we can verify what a supplier holds and ask the right questions early. If your product may be a controlled substance, book a free sourcing review before you request samples.