Mercury in cosmetics must now be zero: Minamata rule and fake whitening creams

Mercury in cosmetics now has to be zero. At the fifth Conference of the Parties to the Minamata Convention on Mercury (COP-5), in late 2023, countries removed the “above 1 ppm” threshold, making it explicit that no mercury may be added to cosmetics at all. Thailand already banned mercury compounds in cosmetics, but the Thai FDA still finds them in whitening creams sold online. This lesson covers what changed, why it keeps turning up, and what to check before you buy.

How the global rule changed

The Minamata Convention was adopted in 2013. It is named after Minamata Bay in Japan, where mercury-laden industrial wastewater poisoned thousands of people in the mid-20th century. It entered into force on 16 August 2017.

When	The rule on cosmetics
Before COP-5	No making, importing or exporting cosmetics with more than 1 ppm mercury, including skin-lightening soaps and creams
COP-5, Geneva, 30 Oct-3 Nov 2023	The 1 ppm threshold removed, making it explicit that no mercury can be added to cosmetics
25 April 2025	The COP-5 annex amendments entered into force for Parties (with listed exceptions)

Where Thailand stands. Thailand acceded on 22 June 2017, and the Convention entered into force for it on 20 September 2017. On joining, Thailand declared that any amendment to an annex will enter into force for it only once it deposits its own instrument for that amendment. For shoppers, that changes nothing: Thai law already lists mercury compounds as substances banned from cosmetics, and the Thai FDA tests for them and publishes what it finds.

Worked example: 1 ppm versus what is actually found

1 ppm (part per million) = 1 milligram per kilogram. Take a 15 g jar of cream (a made-up size):

1. At 1 ppm: 15 g = 0.015 kg → 1 × 0.015 = 0.015 mg of mercury
2. In 2023, a group of environmental organisations bought 213 suspect skin-lightening products from 23 online platforms in many countries, including Thailand. 191 of them (90%) were above 1 ppm, with the highest at 74,800 ppm.
3. 74,800 ppm = 74,800 ÷ 1,000,000 = 7.48% → 15 g × 0.0748 = 1.12 g
4. Compared: 1.12 g = 1,120 mg; 1,120 ÷ 0.015 ≈ 74,700 times the old threshold.

The point is that the problem is not trace contamination. It is illegal creams with mercury as a main ingredient, added for fast whitening. Setting the limit at zero removes any room to argue that “there is only a little”.

Why it still turns up in Thailand

Mercury lightens skin by suppressing melanin, so illegal creams add it to show quick results. WHO notes that even where controls are tight, such products can still be found advertised and sold online.

A Thai example: in January 2024 the Thai FDA published results for 16 cosmetics it had ordered from online shops. All 16 contained banned substances, including mercury compounds, steroids, hydroquinone and retinoic acid, and some were expired or had no expiry date. The Thai FDA warned that mercury creams can cause allergy, red rashes, darkened facial skin and thinner skin, and that mercury builds up in the body and can inflame the urinary tract and kidneys.

WHO adds that reported kidney effects range from protein in the urine to kidney failure, and the environmental groups’ report stresses that mercury is a neurotoxin, with long-term use able to affect the eyes, lungs, kidneys, digestive system and immune system.

A cream that whitens unusually fast is not a great formula. It is a reason to be suspicious.

Warning signs before you buy

What you see	Why to be careful
No Thai label, or an incomplete one	Thai law requires the product name, type, ingredients, directions, maker or importer, net quantity, batch, manufacturing date and notification number
No notification number, or one you cannot find in the Thai FDA system	Selling cosmetics that were never notified is illegal
A number, but the product name or maker does not match	It may be another product’s number
Claims of unusually fast whitening, or clearing melasma and dark spots in days	Mercury suppresses pigment, which is why illegal creams use it for quick results
A plain unlabelled pot, decanted cream, called a “base” or “secret formula”	Nobody is accountable for what is inside
A seller with no fixed address	The Thai FDA advises buying from shops with a fixed, known location

Checking a notification number yourself

A Thai cosmetic notification number is 10 or 13 digits. You can look it up in the product-check system on the Thai FDA website, the Oryor Smart Application, or LINE @FDAThai. When you find it, check that the product name, type, and maker or importer all match the jar. Step-by-step instructions are in Reading a cosmetic ingredient list.

Remember that a notification number only proves the product was notified to the Thai FDA. It does not prove the jar in your hand is genuine.

If you have already used it

1. Stop now. Do not finish the jar.
2. Keep the jar, box and proof of purchase. Do not throw them away; they are evidence for both your doctor and the Thai FDA.
3. See a doctor if you have a rash, thinning, darkening or blotchy skin, or anything else unusual. Say which cream you used and for how long, and take it with you. If you are pregnant, see a doctor promptly.
4. Report it to the Thai FDA on 1556, LINE @FDAThai, or your provincial public health office.

Common mistakes

• Believing fast whitening means it works well. Unusually fast results are a reason to be suspicious.
• Only checking that a number exists, without checking it matches the product and maker.
• Buying on social media reviews and before-and-after photos. Photos tell you nothing about what is inside.
• Using it up because you paid for it. Mercury builds up in the body.
• Throwing the jar away after a reaction. Then neither your doctor nor the Thai FDA has anything to go on.

Sources

• Minamata Convention COP-5 takes crucial steps in its mission of eliminating mercury pollution — UNEP
• Adopted amendments to annexes A and B — Minamata Convention on Mercury
• Thailand: Accession, Minamata Convention on Mercury (C.N.332.2017) — United Nations Treaty Collection
• Mercury and health — World Health Organization
• Thai FDA warns of 16 cosmetics with banned substances sold online (in Thai) — Prachachat Turakij
• Toxic mercury cosmetics still marketed as a ‘solution’ to dark skin — European Environmental Bureau