BHT exposure measured in urine across five countries
What it found
BHT was found in 88% of urine samples from people in China, India, Japan, Saudi Arabia and the United States.
Estimated daily intakes were higher in children than adults, and some exceeded the European acceptable daily intake.
What they found
Studies in people
BHT in urine
BHT was found in 88% of the urine samples, at levels from below the limit of quantification up to 15 ng/mL. The median level was 1.26 ng/mL.
BHT metabolites
Four BHT metabolites were found in 48% to 89% of samples. BHT-COOH was the most common and was found at the highest levels, with a median of 1.78 ng/mL.
BHA in urine
BHA was found in 39% of the urine samples, at levels up to 4.31 ng/mL.
Estimated daily intake
Using a model, the authors estimated daily BHT intake from urine levels. For children it ranged from 0.38 to 613 micrograms per kilogram body weight per day, and for adults from 0.21 to 372 micrograms per kilogram body weight per day.
Intake above ADI
When using one of the two models, the highest estimated intakes for children in Japan, India and the United States were above the European Food Safety Authority acceptable daily intake of 0.25 mg/kg body weight per day.
Country differences
The highest median levels of total synthetic phenolic antioxidants were in urine from India, Japan and the United States. Estimated intakes were highest for Japan.
What the authors conclude
“This study demonstrates universal exposure to BHT by populations across several countries.”
Also in their conclusions
- They say this study shows widespread exposure to BHT across several countries.
- They note that while diet is thought to be the main source, other routes such as indoor air, dust and personal care products cannot be ruled out.
- They suggest the need to identify sources of BHT exposure in Japan, India and the United States.
How it was done
The authors wanted to measure human exposure to synthetic phenolic antioxidants like BHT, because little was known about how much people are actually exposed to these chemicals.
They collected 145 spot urine samples from people aged 2 to 87 in China, India, Japan, Saudi Arabia and the United States between 2010 and 2012. They measured BHT, BHA and four BHT metabolites in the urine and used the levels to estimate daily intake.
What it can’t tell you
- This study measured BHT and its metabolites in urine at one point in time, so it cannot show how exposure changes over time or what health effects might occur.
- The samples came from a limited number of people in each country, so the levels may not represent the whole population.
- The estimated daily intakes rely on assumptions and models, so they come with uncertainty.
Who paid
- Funding
- Funded by NIEHS NIH HHS (from the PubMed record).
- Conflicts
- Competing interests. All authors declare that they have no competing interests.
- Authors work at
- State University of New York at Albany, United States; King Abdulaziz University, Saudi Arabia
The paper
- Title
- Quantitative identification of and exposure to synthetic phenolic antioxidants, including butylated hydroxytoluene, in urine
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Wang W, Kannan K (2019). Quantitative identification of and exposure to synthetic phenolic antioxidants, including butylated hydroxytoluene, in urine. Environment international. doi:10.1016/j.envint.2019.04.028Free full textPubMed 31029976DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error