Is orange Thai tea dangerous?

The colour is a permitted one, and within the limit it is considered acceptable. The problems are that some samples go over the limit and that several cups a day add up. Drinking it in moderation and mixing in other drinks lowers the risk.

Does the colour cause hyperactivity in children?

There is no firm answer. The Thai FDA says no scientific data confirms it. The EU requires products with this colour to carry a warning that it may affect activity and attention in children. If you are worried about your child, ask a paediatrician.

Can I get Thai tea without colouring?

Yes. Some producers now make uncoloured Thai tea. It brews a natural reddish brown like any black tea, not bright orange. Check that the label does not list a synthetic colour.

Why Thai tea is orange: Sunset Yellow, the Thai FDA limit and what tests found

The bright orange of Thai iced tea does not come from the tea leaf. It comes from a synthetic food colour called Sunset Yellow FCF (INS 110, or E110 in Europe), which the Thai FDA allows in flavoured tea drinks up to a set limit. Several rounds of testing in 2025 found products both inside and over that limit. This article covers what the law allows, what the tests found, and what a drinker can check.

Why Thai tea is orange

Thai tea is made from black tea, which brews to a reddish brown, not the glowing orange you see in the cup. That orange is added to the tea powder at the factory. The colour used most is Sunset Yellow FCF, and some tests also found other colours mixed in, such as Tartrazine, Ponceau 4R, Carmoisine and Brilliant Blue.

The Thai FDA splits tea into two groups:

Dried tea leaves, plain tea powder and herbal infusions, which have their own natural colour, may not contain added colour, except caramel.
Flavoured tea drinks, such as Thai milk tea or ready-to-drink green tea, may contain colour within the limit.

So if a tea powder is bright orange, it is a flavoured tea, and the label has to say a colour is used.

The Thai FDA limit

As the Thai FDA explains in its infographic on colour in tea:

Case	Limit
One colour	Up to 100 ppm (100 mg per kg)
Several colours	All colours together up to 100 ppm
Measured as	The drink ready to consume, not the dry powder
Plain tea leaves, plain powder, herbal tea	No colour, except caramel

The FDA says the limit is in line with the international Codex standard. In February 2025 its Secretary-General said in an interview that ready-mix tea powder may contain Sunset Yellow up to 100 ppm. The food additive rules in force are in Ministry of Public Health Notification No. 444 (B.E. 2566, 2023).

One news report gave a different example from the same notification: milk-based drinks have a lower ceiling for Sunset Yellow, 70 mg/kg. It did not say whether Thai tea falls in that group. The number that applies depends on which food category a product is filed under. This article uses the 100 ppm the FDA gives for tea.

What the 2025 tests found

The Consumers Foundation, Chalaadsue magazine and the Consumer Council of Thailand tested Thai tea in several rounds. Brands are not named here.

Round	Samples	Result
Collected Nov 2024, published Feb 2025	20 instant tea powders, Bangkok area	1 to 5 synthetic colours each; 17 samples (85%) used more than one; half had no ingredient breakdown on the label
Collected Mar 2025, published Apr 2025	15 Thai milk teas from chain outlets	Synthetic colour in every cup, 1 to 4 colours each; Sunset Yellow in every cup, from 7.90 to 291.41 mg/kg
Collected Aug 2025, published Nov 2025	15 instant tea powders	11 samples (73%) did not meet the legal criteria; 4 passed

The FDA gives another side. Its Secretary-General said in early 2025 that it samples ready-mix tea powder every year and had found no colour problems over the previous 4 to 5 years. It had found some products failing on other standards, such as certain heavy metals over the limit, and had taken legal action. The two sides sampled different products at different times, so the figures do not directly contradict each other. Together they say the market has good and bad products side by side.

Some drink stalls mix powders from several brands in one cup, so the colour from each can add up even if every bag passes on its own.

Worked example: how much colour is in one cup

Safety is judged against the ADI, the amount a person can take in every day for life without harm. For Sunset Yellow, the FAO/WHO expert committee (JECFA) and EFSA set it at 0 to 4 mg per kg of body weight per day.

Say a glass of Thai iced tea holds 300 g of tea (0.3 kg, not counting ice).

A cup coloured right at the 100 mg/kg limit: 0.3 × 100 = 30 mg of colour.
A cup matching the highest sample found, 291.41 mg/kg: 0.3 × 291.41 ≈ 87 mg.
ADI for a 60 kg adult: 4 × 60 = 240 mg a day.
ADI for a 20 kg child: 4 × 20 = 80 mg a day.

Cup	Adult, 60 kg	Child, 20 kg
30 mg (at the limit)	12.5% of ADI	37.5% of ADI
87 mg (highest found)	about 36% of ADI	about 109%, over the ADI

One cup a day within the limit leaves an adult far below the ADI. A small child drinking one strongly coloured cup over the limit can pass it with that single cup. These are worked numbers: the milk tea report did not say exactly how the samples were measured, and the ADI is about daily intake over a lifetime, so one day over does not mean someone will fall ill.

One over-limit glass comes close to a child's ADI

Hyperactivity: what the evidence says

The sources do not agree here.

The Thai FDA says no scientific data confirms that this colour in Thai tea causes hyperactivity in children, and that Thailand has no reports of harm from it.
The European Union, after a study at the University of Southampton, requires food and drink containing six colours, Sunset Yellow among them, to carry a label warning that they may affect activity and attention in children. EFSA, for its part, concluded that the available data did not establish a causal link.

So nothing is proven, but there is reason for care with children. The FDA’s Secretary-General advised that children under 6 should avoid these drinks, and that adults keep to 1 to 2 cups a day depending on the product. Thai tea also carries sugar, sweetened condensed milk and caffeine, which are reasons enough to drink it in moderation. If your child has attention problems, talk to a paediatrician rather than acting on headlines.

Buying powder and ordering Thai tea

The FDA’s advice works for people who brew at home and people who buy a cup:

Choose products with a Thai FDA number. A registered product can be traced; without the number you cannot tell who is responsible for it.
Read the colour line. If colour is used, the label must say “synthetic colour” or “natural colour” with the INS number or the colour’s name, for example INS 110.
Look at the brewed colour. A reddish brown that is not too vivid is a better sign than glowing orange.
Rotate your drinks. Do not drink several cups of Thai tea every day, so you are not taking the same colour again and again.
Brewing at home, use less powder. Weaker tea means less colour in proportion.

Common mistakes

Thinking orange is the true colour of tea. Real black tea brews reddish brown. Bright orange is added.
Comparing a dry-powder figure with the limit. The 100 ppm limit is for the drink as served. Unbrewed powder is far more concentrated, so check how a number was measured before worrying.
Believing the colour is banned across Europe. It is still allowed there, with a compulsory warning on the label.
Giving small children a big cup every day. A smaller body means a smaller ADI, so the same cup is a much larger share for a child than for an adult.

Thai tea is not forbidden. Pick products with complete labels, drink it now and then, and keep it away from small children.

Summary

The orange in Thai tea is Sunset Yellow FCF, allowed up to 100 ppm in the ready-to-drink form. The 2025 tests show the market holds products both within and over the limit. What you can do yourself: look for the FDA number, read the colour on the label, and do not drink several cups every day. For ice and drinks from street stalls, see ice, drinking water and iced drinks, and to cut the sugar too, see ordering Thai food with less salt and sugar.

Sources

Ingredients and heat vary by kitchen and recipe. If you have a food allergy, ask before you order, every time.