Chemistry:Butylated hydroxytoluene

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Short description: Antioxidant
"E321" redirects here. For the Italian electric locomotive, see FS Class E.321.
Butylated hydroxytoluene
Skeletal formula of butylated hydroxytoluene
Ball-and-stick model of the butylated hydroxytoluene molecule
Names
Preferred IUPAC name
2,6-Di-tert-butyl-4-methylphenol
Other names
  • 2,6-Di-tert-butyl-p-cresol
  • 2,6-DI-tert-butyl-4-methylphenol
  • 3,5-Di-tert-butyl-4-hydroxytoluene
  • 2,6 ditertiary-butyl-4-methyl phenol
  • DBPC
  • BHT
  • E321
  • AO-29
  • Avox BHT
  • Antioxidant 264
  • Additin RC 7110
  • Dibutylated hydroxytoluene
  • 4-Methyl-2,6-di-tert-butyl phenol
  • 3,5-(Dimethylethyl)-4-hydroxytoluene
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
EC Number
  • 204-881-4
KEGG
RTECS number
  • GO7875000
UNII
Properties
C15H24O
Molar mass 220.356 g/mol
Appearance White to yellow powder
Odor Slight, phenolic
Density 1.048 g/cm3
Melting point 70 °C (158 °F; 343 K)[4]
Boiling point 265 °C (509 °F; 538 K)[4]
1.1 mg/L (20 °C)[1]
log P 5.32[2]
Vapor pressure 0.01 mmHg (20 °C)[3]
Hazards
Main hazards Flammable
Safety data sheet [5]
GHS pictograms GHS09: Environmental hazard
GHS Signal word Warning
H410
P273, P391, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondFlammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
2
0
Flash point 127 °C (261 °F; 400 K)[4]
Lethal dose or concentration (LD, LC):
> 2,000 mg/kg (dermal, rat)[6]
NIOSH (US health exposure limits):
PEL (Permissible)
 None[3]
REL (Recommended)
 TWA 10 mg/m3[3]
IDLH (Immediate danger)
 N.D.[3]
Related compounds
Related compounds
 Butylated hydroxyanisole
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Tracking categories (test):

Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties and is widely used as a food preservative in different parts of the world. [7] BHT is widely used to prevent free radical-mediated oxidation in fluids (e.g. fuels, oils) and other materials, and the regulations overseen by the US FDA—which considers BHT to be "generally recognized as safe"—allow small amounts to be added to foods.

Yet, according to the Environmental Working Group that does independent analyses and compiles peer-reviewed research, BHT is shown in multiple studies to cause damage to cells through production of metabolites and oxidative stress (Xu et al., 2021). These are mechanisms associated with a number of diseases including cancer. BHT is not a listed carcinogen, but some data have shown that it does cause cancer in animals. In high dose studies in animals it has been linked to hepatic toxicity, and the promotion of tumors in the liver, bladder, and lungs (Liu & Mabury, 2020; Xu et al., 2021). BHT has been shown to cause developmental effects and thyroid changes in animals, suggesting that it may be able to disrupt endocrine signaling (European Food Safety Authority,2012).

In certain high exposure scenarios, EFSA noted that children's dietary intake of BHT could exceed its acceptable daily intake, or ADI.

Natural occurrence

Phytoplankton, including the green algae Botryococcus braunii, as well as three different cyanobacteria (Cylindrospermopsis raciborskii, Microcystis aeruginosa and Oscillatoria sp.) are capable of producing BHT as a natural product.[8] The fruit lychee also produces BHT in its pericarp.[9]

Several fungi (for example Aspergillus conicus) living in olives produce BHT. Volatile organic compounds such as BHT and cresol are produced by resident fungi when olives are being stored awaiting pressing.[10]

It has been detected in higher plants and herbivorous insects, but it is not clear whether the BHT is produced by the plant, the insect, or some other organism living in association.[11]

Production

Industrial production

The chemical synthesis of BHT in industry has involved the reaction of p-cresol (4-methylphenol) with isobutylene (2-methylpropene), catalyzed by sulfuric acid: [12]

CH3(C6H4)OH + 2 CH2=C(CH3)2 → ((CH3)3C)2CH3C6H2OH

Reactions

The species behaves as a synthetic analog of vitamin E, primarily acting as a terminating agent that suppresses autoxidation, a process whereby unsaturated (usually) organic compounds are attacked by atmospheric oxygen. BHT stops this autocatalytic reaction by converting peroxy radicals to hydroperoxides. It effects this function by donating a hydrogen atom:

RO2• + ArOH → ROOH + ArO•
RO2• + ArO• → nonradical products

where R is alkyl or aryl, and where ArOH is BHT or related phenolic antioxidants. Each BHT consumes two peroxy radicals.[13][14] The electron-donating alkyl groups on the ortho and para positions of BHT increase the electron density of the phenolic hydroxyl moiety through the inductive effect and the hyperconjugation effect,[15] reduce the bond dissociation energy of the phenolic hydroxyl group, and enhance its reactivity to lipid free radicals. Meanwhile, the phenoxy radical generated by BHT is stabilized due to the delocalization of unpaired electrons around the aromatic ring[15][16] and the steric hindrance effect of ortho tert-butyl groups.[17][18] Isobutene is one of the possible degradation products formed by BHT oxidation with computational studies suggesting that there are two possible mechanism that can lead to isobutene formation with the OH addition pathways at the C2 site of BHT more likely to result in isobutene formation than pathways of H abstracts from the t-butyl group.[19]

Applications

BHT is listed by the NIH Hazardous Substances Data Bank under several categories in catalogues and databases, such as food additive, household product ingredient, industrial additive, personal care product and cosmetic ingredient, pesticide ingredient, plastic and rubber ingredient and medical and veterinary research.[20]

Food additive

BHT is primarily used as an antioxidant food additive.[21] In the United States, it is classified as generally recognized as safe (GRAS) based on a National Cancer Institute study from 1979 in rats and mice.[22][23] Recent research, however indicates reasons for health concerns (see Health effects section below for more details). Recently, as EWG states: "BHT was shown in multiple studies to cause damage to cells through production of metabolites and oxidative stress (Xu et al., 2021). These are mechanisms associated with a number of diseases including cancer. BHT is not a listed carcinogen, but some data have shown that it does cause cancer in animals. In high dose studies in animals it has been linked to hepatic toxicity, and the promotion of tumors in the liver, bladder, and lungs (Liu & Mabury, 2020; Xu et al., 2021). BHT has been shown to cause developmental effects and thyroid changes in animals, suggesting that it may be able to disrupt endocrine signaling (European Food Safety Authority,2012).[24]

In certain high exposure scenarios, EFSA noted that children's dietary intake of BHT could exceed its acceptable daily intake, or ADI. Also, BHT is commonly consumed with other compounds in ultra-processed food (UPF), raising children's food additive levels. There are data gaps for multiple routes of BHT exposure and how well it is absorbed, as well as health effects of co-exposure with other synthetic phenolic antioxidants (Liu & Mabury, 2020)."[25]

It is approved for use in the U.S. by the Food and Drug Administration: For example, 21 CFR § 137.350(a)(4) allows BHT up to 0.0033% by weight in "enriched rice",[26] while 9 CFR § 381.147](f)(1) allows up to 0.01% in poultry "by fat content".[27] It is permitted in the European Union under E321.[28]

A reassessment of BHT safety was planned by the FDA for February, 2026. (EWG).[29]

BHT is used as a preservative ingredient in some foods. With this usage BHT maintains freshness or prevents spoilage; it may be used to decrease the rate at which the texture, color, or flavor of food changes.[30]

Some food companies have voluntarily eliminated BHT from their products or have announced that they were going to phase it out.[31]

Antioxidant

BHT is also used as an antioxidant in products such as metalworking fluids, cosmetics, pharmaceuticals, rubber, transformer oils, and embalming fluid.[32][33] In the petroleum industry, where BHT is known as the fuel additive AO-29 (Innospec), it is used in hydraulic fluids, turbine and gear oils, and jet fuels.[32][34] BHT is also used to prevent peroxide formation in organic ethers and other solvents and laboratory chemicals.[35] It is added to certain monomers as a polymerisation inhibitor to facilitate their safe storage.[36] Some additive products contain BHT as their primary ingredient, while others contain the chemical merely as a component of their formulation, sometimes alongside butylated hydroxyanisole (BHA).[37]

BHT is also added as an antioxidant in consumer products such as polyurethane, which is used in mattresses, plastics, carpets and printing inks. From these products, it can migrate into the air and settle in house dust. [38]

Although food is the most significant source of BHT exposure, dust has been reported to be an important source indoors (Liu & Mabury 2020), especially in children, who ingest more dust, on average (Wang et al 2015).[39]

Cosmetics

The European Union restricts the use of BHT in mouthwash to 0.001% concentration, in toothpaste to 0.01% concentration, and to 0.8% in other cosmetics.[40]

Food packaging label "no BHT in food packaging"

Health effects

Like many closely related phenolic antioxidants, BHT has low acute toxicity[6] (e.g., the desmethyl analog of BHT, 2,6-di-tert-butylphenol, has an -1">50 of >9 g/kg[12]). The US Food and Drug Administration classifies BHT as generally recognized as safe (GRAS) food preservative when used in an approved manner.[41][42] In 1979, the National Cancer Institute determined that BHT was noncarcinogenic in a mouse model.[22] Yet recent research suggests reason for concern (see below).

The World Health Organization discussed a possible link between BHT and cancer risk in a 1986 report concluding there is limited evidence for carcinogenicity from animal studies.[43] Primary research studies in the 1970s–1990s reported both potential for increased risk and potential for decreased risk in the area of oncology.[44] Even at that time, increased cancer risk was therefore acknowledged. A review report published in 2002 noted that BHT has shown anticarcinogenic effects, no effect, or tumor promoting effects depending on animal species and target organ considered.[44] Because of this uncertainty, the Center for Science in the Public Interest puts BHT in its "caution" column and recommends avoiding it.[45]

from EWG: "The breakdown of BHT in the body into metabolites produces reactive intermediates that may pose risks to human health. While the cytotoxicity of BHT has long been recognized, recent studies published after its major regulatory evaluations have further clarified the precise mechanisms behind this cellular damage. [46]

The tumor-promoting effects of BHT are mainly influenced by production of quinone methylation metabolites such as BHT-QM (Xu et al., 2021). Its metabolites are electrophilic, which means they bind well to cellular proteins and DNA (Lanigan and Yamarik, 2002). [47]

Like BHA, its metabolite production causes oxidative stress, DNA damage and cell death (Castro et al., 2017). While BHT is not considered a carcinogen by IARC, its mechanisms are related to carcinogenesis. [48]

High-dose animal studies have linked BHT exposure to hepatic toxicity, endocrine disruption and the promotion of tumors in the liver, bladder, and lungs (Liu & Mabury 2020; Xu et al., 2021). Oral studies in rats showed renal and hepatic damage at acute doses of 0.5 to 1.0 g/kg (Lanigan and Yamarik 2002). Subacute exposure at lower doses was linked to liver toxicity in rats (Moon et al., 1987). [49]

BHT has been found in human cord blood (Du et al., 2019), breast milk (Zhang et al., 2020), serum (Liu & Mabury 2018), urine (Liu & Mabury 2018) and adipose tissue (Collings & Sharratt, 1970).[50]

An exposure study conducted in 2019 found that U.S. residents had some of the highest levels of BHT, compared to other countries, with the highest exposures exceeding the ADI (Wang & Kannan, 2019)."[51]

References

  1. ↑ KEMI Anställd [KEMI Staff] (1994). "Teknisk beskrivning av ämnet—2,6-Bis(tert-butyl)-4-metylfenol 1994 [Information on substances—2,6-Bis(tert-butyl)-4-methylphenol 1994"] (in sv,en). Sundyberg, SE: KEMI [Swedish Chemicals Agency]. http://apps.kemi.se/flodessok/floden/kemamne/BHT.htm. "Vattenlöslighet: 1,1 mg/L (20 °C) [Water solubility: 1.1 mg/L (20 °C)]" 
  2. ↑ "2,6-di-tert-butyl-4-methylphenol". https://www.chemsrc.com/en/cas/128-37-0_1067745.html. 
  3. ↑ 3.0 3.1 3.2 3.3 NIOSH Pocket Guide to Chemical Hazards. "#0246". National Institute for Occupational Safety and Health (NIOSH). https://www.cdc.gov/niosh/npg/npgd0246.html. 
  4. ↑ 4.0 4.1 4.2 "ICSC 0841 - BUTYLATED HYDROXYTOLUENE". March 1999. http://www.inchem.org/documents/icsc/icsc/eics0841.htm. 
  5. ↑ "Safety data for 2,6-di-tert-butyl-p-cresol". http://ptcl.chem.ox.ac.uk/MSDS/DI/2,6-di-t-butyl-p-cresol.html. 
  6. ↑ 6.0 6.1 Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  7. ↑ "Understanding the Chemistry Behind the Antioxidant Activities of Butylated Hydroxytoluene (BHT): A Review". Eur. J. Med. Chem. 101: 295–312. 28 August 2015. doi:10.1016/j.ejmech.2015.06.026. PMID 26150290. 
  8. ↑ "Production of Natural Butylated Hydroxytoluene as an Antioxidant by Freshwater Phytoplankton". Journal of Phycology 44 (6): 1447–1454. December 2008. doi:10.1111/j.1529-8817.2008.00596.x. PMID 27039859. Bibcode: 2008JPcgy..44.1447B. http://ntur.lib.ntu.edu.tw/bitstream/246246/162863/1/22.pdf. 
  9. ↑ Jiang, G; Lin, S; Wen, L; Jiang, Y; Zhao, M; Chen, F; Prasad, KN; Duan, X et al. (15 January 2013). "Identification of a novel phenolic compound in litchi (Litchi chinensis Sonn.) pericarp and bioactivity evaluation.". Food Chemistry 136 (2): 563–8. doi:10.1016/j.foodchem.2012.08.089. PMID 23122098. 
  10. ↑ Gharbi, Ines; Issaoui, Manel; El Gharbi, Sinda; Gazzeh, Nour-Eddine; Tekeya, Meriem; Mechri, Beligh; Flamini, Guido; Hammami, Mohamed (2017). "Butylated hydroxytoluene (BHT) emitted by fungi naturally occurring in olives during their pre-processing storage for improving olive oil stability". European Journal of Lipid Science and Technology 119 (11). doi:10.1002/ejlt.201600343. 
  11. ↑ Zhao, F; Wang, P; Lucardi, RD; Su, Z; Li, S (6 January 2020). "Natural Sources and Bioactivities of 2,4-Di-Tert-Butylphenol and Its Analogs.". Toxins 12 (1): 35. doi:10.3390/toxins12010035. PMID 31935944. 
  12. ↑ 12.0 12.1 Helmut Fiege, Heinz-Werner Voges, Toshikazu Hamamoto, Sumio Umemura, Tadao Iwata, Hisaya Miki, Yasuhiro Fujita, Hans-Josef Buysch, Dorothea Garbe, Wilfried Paulus "Phenol Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. doi:10.1002/14356007.a19_313 Article Online Posting Date: June 15, 2000.
  13. ↑ Burton G. W., Ingold K. U. (1981). "Autoxidation of biological molecules. 1. Antioxidant activity of vitamin E and related chain-breaking phenolic antioxidants in vitro". Journal of the American Chemical Society 103 (21): 6472–6477. doi:10.1021/ja00411a035. Bibcode: 1981JAChS.103.6472B. 
  14. ↑ Fujisawa, Seiichiro; Kadoma, Yoshinori; Yokoe, Ichiro (July 2004). "Radical-scavenging activity of butylated hydroxytoluene (BHT) and its metabolites" (in en). Chemistry and Physics of Lipids 130 (2): 189–195. doi:10.1016/j.chemphyslip.2004.03.005. PMID 15172835. https://linkinghub.elsevier.com/retrieve/pii/S0009308404000349. 
  15. ↑ 15.0 15.1 Huang, Mou-Tuan, ed (1992-10-01). "Thermal Degradation of Phenolic Antioxidants" (in en). Phenolic Compounds in Food and Their Effects on Health II: Antioxidants and Cancer Prevention. ACS Symposium Series. 507. Washington, DC: American Chemical Society. pp. 200–218. doi:10.1021/bk-1992-0507.ch015. ISBN 978-0-8412-2476-6. https://pubs.acs.org/doi/abs/10.1021/bk-1992-0507.ch015. 
  16. ↑ Shahidi, Fereidoon; Janitha, P. K.; Wanasundara, P. D. (1992). "Phenolic antioxidants" (in en). Critical Reviews in Food Science and Nutrition 32 (1): 67–103. doi:10.1080/10408399209527581. ISSN 1040-8398. PMID 1290586. https://www.tandfonline.com/doi/abs/10.1080/10408399209527581. 
  17. ↑ Breese, K.D.; Lamèthe, J.-F.; DeArmitt, C. (2000). "Improving synthetic hindered phenol antioxidants: learning from vitamin E" (in en). Polymer Degradation and Stability 70 (1): 89–96. doi:10.1016/S0141-3910(00)00094-X. https://linkinghub.elsevier.com/retrieve/pii/S014139100000094X. 
  18. ↑ Ariffin, Azhar; Rahman, Noorsaadah Abdul; Yehye, Wageeh A.; Alhadi, Abeer A.; Kadir, Farkaad A. (2014). "PASS-assisted design, synthesis and antioxidant evaluation of new butylated hydroxytoluene derivatives" (in en). European Journal of Medicinal Chemistry 87: 564–577. doi:10.1016/j.ejmech.2014.10.001. PMID 25299680. https://linkinghub.elsevier.com/retrieve/pii/S0223523414009271. 
  19. ↑ Zhou, Junwei; Chen, Hongrui; Chen, Jianfa; Wan, Daihong; Zhang, Huikun; Wang, Rong; Xie, Daiqian; Mao, Chengli (2022-05-26). "Mechanisms and Kinetics Studies of Butylated Hydroxytoluene Degradation to Isobutene" (in en). The Journal of Physical Chemistry A 126 (20): 3210–3218. doi:10.1021/acs.jpca.2c01961. ISSN 1089-5639. PMID 35549278. Bibcode: 2022JPCA..126.3210Z. https://pubs.acs.org/doi/10.1021/acs.jpca.2c01961. 
  20. ↑ US Dept of Health & Human Services. Household Products Database. [1] .US EPA. InertFinder. [2]. US National Library of Medicine. Haz-Map. [3] . US National Library of Medicine. Hazardous Substances Data Bank. [4].
  21. ↑ "CFR - Code of Federal Regulations Title 21". https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=172.115. 
  22. ↑ 22.0 22.1 Bioassay of Butylated Hydroxytoluene (BHT) for Possible Carcinogenicity, National Cancer Institute, CARCINOGENESIS Technical Report Series No. 150, 1979, 128 pp National Institutes of Health
  23. ↑ "Abstract for TR-150" (in en). https://ntp.niehs.nih.gov/publications/reports/tr/tr150. 
  24. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  25. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  26. ↑ "CFR - Code of Federal Regulations Title 21". https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=137.350. 
  27. ↑ "9 CFR 3, Part 381.147 (Restrictions on the Use of Substances in Poultry Processing)". https://www.fda.gov/Food/FoodSafety/RetailFoodProtection/FoodCode/FoodCode2001/ucm092716.htm. 
  28. ↑ "Scientific Opinion on the re-evaluation of butylated hydroxytoluene BHT (E 321) as a food additive | European Food Safety Authority". 7 March 2012. http://www.efsa.europa.eu/en/efsajournal/pub/2588. 
  29. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  30. ↑ "Food Additives & Ingredients > Overview of Food Ingredients, Additives & Colors". 20 February 2020. https://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm094211.htm#types. "Types of Ingredients: Preservatives[.] What They Do: Prevent food spoilage from [...]; maintain freshness[.] Examples of Uses: Fruit sauces and jellies, beverages, baked goods, cured meats, oils and margarines, cereals, dressings, snack foods, fruits and vegetables[.] Names Found on Product Labels: Ascorbic acid, citric acid, sodium benzoate, calcium propionate, sodium erythorbate, sodium nitrite, calcium sorbate, potassium sorbate, BHA, BHT, EDTA, tocopherols (Vitamin E)[.]" 
  31. ↑ Hamblin, James (11 February 2015). "The Food Babe: Enemy of Chemicals". The Atlantic. https://www.theatlantic.com/health/archive/2015/02/the-food-babe-enemy-of-chemicals/385301/. Retrieved 12 September 2015. 
  32. ↑ 32.0 32.1 Yehye, Wageeh A.; Rahman, Noorsaadah Abdul; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A.; Kadir, Farkaad A.; Yaeghoobi, Marzieh (2015-08-28). "Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): a review". European Journal of Medicinal Chemistry 101: 295–312. doi:10.1016/j.ejmech.2015.06.026. ISSN 1768-3254. PMID 26150290. 
  33. ↑ PubChem. "Butylated Hydroxytoluene" (in en). https://pubchem.ncbi.nlm.nih.gov/compound/31404. 
  34. ↑ Ash, Michael, ed (2009). Handbook of preservatives. Endicott, NY: Synapse Information Resources. p. 628. ISBN 978-1-890595-66-1. 
  35. ↑ "Solvents". https://www.sigmaaldrich.com/chemistry/solvents/learning-center/stabilizer-systems.html. 
  36. ↑ Grohmann, Caio Vinícius Signorelli; Sinhoreti, Mário Alexandre Coelho; Soares, Eveline Freitas; Oliveira, Robson Ferraz de; Souza, Eduardo José de Carvalho; Geraldeli, Saulo (24 June 2022). "Effect of a polymerization inhibitor on the chemomechanical properties and consistency of experimental resin compo". Brazilian Dental Journal 33 (3): 92–98. doi:10.1590/0103-6440202204242. PMID 35766722. 
  37. ↑ "BHA and BHT: A Case for Fresh?". Scientific American. 19 December 2013. https://www.scientificamerican.com/article/bha-and-bht-a-case-for-fresh/. 
  38. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  39. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  40. ↑ Slavova, Siana (23 June 2023). "New restrictions for Butylated Hydroxytoluene (BHT) and Acid Yellow 3 apply as of July 2023" (in en). https://www.obelis.net/news/new-restrictions-bht-acid-yellow-3-cosmetic-products/. 
  41. ↑ "SCOGS (Select Committee on GRAS Substances)". FDA.gov. https://www.accessdata.fda.gov/scripts/fdcc/?set=SCOGS. 
  42. ↑ "CFR—Code of Federal Regulations Title 21". FDA.gov. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?fr=172.115. 
  43. ↑ Butylated hydroxytoluene (BHT) (Report). 40. World Health Organization: International Agency For Research On Cancer. 1986. p. 191. https://monographs.iarc.fr/ENG/Monographs/vol1-42/mono40.pdf. 
  44. ↑ 44.0 44.1 Lanigan, R. S.; Yamarik, T. A. (2002). "Final Report on the Safety Assessment of BHT" (in en). International Journal of Toxicology 21 (2_suppl): 19–94. doi:10.1080/10915810290096513. ISSN 1091-5818. PMID 12396675. https://journals.sagepub.com/doi/10.1080/10915810290096513. 
  45. ↑ "Two Preservatives to Avoid?". University of California Berkeley. February 1, 2011. http://www.berkeleywellness.com/healthy-eating/food-safety/article/two-preservatives-avoid. 
  46. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  47. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  48. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  49. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  50. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 
  51. ↑ "EWG evaluation of food chemicals: BHT | Environmental Working Group" (in en). 2026-06-22. https://www.ewg.org/research/ewg-evaluation-food-chemicals-bht. 



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