Source library
Why this page exists
Every citation on SpiceHQ points here, so a source can be assessed once and that assessment flows through to every claim depending on it. The scope note on each entry matters as much as the citation: Kew is authoritative on botanical identity and silent on flavour, and treating it otherwise would be misusing it.
American Spice Trade Association — cleanliness specifications and analytical methods
Industry bodymedium reliabilityAmerican Spice Trade Association
Trade cleanliness specifications and colour measurement conventions. An industry body, so commercially interested.
Assessment report on Foeniculum vulgare Miller, fructus
Governmenthigh reliabilityEuropean Medicines Agency, Committee on Herbal Medicinal Products (HMPC)
Regulatory review of fennel fruit as a herbal medicine: composition, the traditional-use evidence base, and the committee’s estragole exposure assessment together with the duration limits it drew from it. Concerns medicinal preparations — teas and extracts taken repeatedly — and states no position on fennel seed used as a spice.
https://www.ema.europa.eu/en/medicines/herbal/foeniculi-dulcis-fructus
Assessment report on Illicium verum Hook. f., fructus
Governmenthigh reliabilityEuropean Medicines Agency, Committee on Herbal Medicinal Products (HMPC)
Regulatory review of star anise fruit, including composition and the documented adulteration of Illicium verum with Illicium anisatum. A medicines assessment, so its dosing context is medicinal rather than culinary.
Assessment report on Zingiber officinale Roscoe, rhizoma
Governmenthigh reliabilityEuropean Medicines Agency, Committee on Herbal Medicinal Products (HMPC)
Regulatory review of ginger rhizome as a herbal medicine: composition, the clinical and traditional-use evidence base, and the contraindications and precautions the committee accepted. A medicines assessment, so its exposures are medicinal preparations rather than food.
https://www.ema.europa.eu/en/medicines/herbal/zingiberis-rhizoma
Chemistry of Spices
Bookhigh reliabilityV. A. Parthasarathy, B. Chempakam, T. J. Zachariah · CABI · 2008
Volatile and non-volatile composition of major spices, and the effect of processing on composition.
ISBN 9781845934057
Cinnamon: Usefulness and Safety
clinical-guidancehigh reliabilityNational Center for Complementary and Integrative Health, National Institutes of Health · 2025
Clinical evidence for cinnamon supplementation, chiefly in type 2 diabetes and blood lipids, and the coumarin question as it bears on cassia. Assesses supplements, not the spice jar.
Codex Alimentarius standards for spices and culinary herbs
Standards bodyhigh reliabilityFAO / WHO Codex Alimentarius Commission
International food standards, including compositional and contaminant limits.
Complementary Health Approaches for Chronic Pain: What the Science Says
clinical-guidancehigh reliabilityNational Center for Complementary and Integrative Health, National Institutes of Health
A clinician-facing summary of the trial evidence for complementary approaches to chronic pain, including topical capsaicin preparations. Its capsaicin evidence concerns creams and plasters applied to skin; nothing in it concerns eating chilli.
Coumarin in flavourings and other food ingredients with flavouring properties — Scientific Opinion of the Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food
Governmenthigh reliabilityEuropean Food Safety Authority · 2008
Tolerable daily intake for coumarin. Directly relevant to cassia cinnamon, which is a significant dietary source.
Dangerous Tastes: The Story of Spices
Bookhigh reliabilityAndrew Dalby · British Museum Press · 2000
History of the spice trade and the documentary record of individual spices in the ancient and medieval world.
ISBN 9780714127200
Drugs and Lactation Database (LactMed)
Governmenthigh reliabilityNational Institute of Child Health and Human Development, National Institutes of Health
Peer-reviewed summaries of what is known about substances in breast milk and their effects on a nursing infant, including herbal products. Competent for lactation questions specifically; it is not a general pregnancy reference and is not an efficacy reference except where it reviews the evidence for a galactagogue claim directly.
Essential Oil and Liquid Potpourri Poisoning in Animals
veterinaryhigh reliabilityMSD Veterinary Manual
Toxicosis from concentrated essential oils in companion animals, including the reason cats are disproportionately affected — deficient glucuronide conjugation, which is the pathway most phenolic compounds are cleared by. Competent for the oils and for the species difference. It is not a source about culinary spice, and the distinction between an oil and the plant it came from is the whole of its relevance here.
Established culinary practice
Customary practiceunassessed reliabilityWidely repeated, consistently observed cooking practice with no single authoritative publication behind it. Cited so that conventional knowledge is visibly labelled as convention rather than presented as research. It is not a substitute for a citation and may never support a safety or health claim.
Evaluation of eugenol and related hydroxyallylbenzene derivatives
Standards bodyhigh reliabilityJoint FAO/WHO Expert Committee on Food Additives (JECFA), WHO Food Additives Series
Toxicological evaluation of eugenol as a flavouring substance, including an acceptable daily intake. The specific current figure must be read from the monograph rather than quoted second-hand, and applies to eugenol as an isolated substance rather than to whole cloves.
FAOSTAT production statistics
Governmenthigh reliabilityFood and Agriculture Organization of the United Nations
National production and trade volumes. Spice categories are aggregated in ways that do not always match culinary categories.
FDA Issues Advisory on Star Anise "Teas"
Governmenthigh reliabilityUnited States Food and Drug Administration · 2003
A regulatory advisory prompted by illness reports associated with star anise infusions, where Chinese star anise was suspected of being mixed with the toxic Japanese species. Relevant to species identity and to infusions specifically, not to ordinary culinary use of verified Illicium verum.
FoodData Central
Governmenthigh reliabilityUnited States Department of Agriculture, Agricultural Research Service
Nutrient composition and standard household-measure gram weights for common foods and spices. Household weights are reference figures for a typical level spoon and do not capture grind, moisture or packing variation.
Garlic and Onion (Allium spp) Toxicosis in Animals
veterinaryhigh reliabilityCristine Hayes · MSD Veterinary Manual · 2024
Mechanism, species susceptibility, reported thresholds and clinical course of Allium poisoning in companion and production animals. Specifically addresses dehydrated and powdered forms, which is what makes it competent for a question about seasoning rather than about vegetables.
Garlic: Usefulness and Safety
clinical-guidancehigh reliabilityNational Center for Complementary and Integrative Health, National Institutes of Health · 2025
Clinical evidence for garlic supplementation in blood lipids, blood pressure and cancer risk, together with bleeding risk and anticoagulant interaction. Concerns supplements; the effect sizes reported are small.
Ginger: Usefulness and Safety
clinical-guidancehigh reliabilityNational Center for Complementary and Integrative Health, National Institutes of Health · 2025
Clinical evidence for ginger across nausea, motion sickness, chemotherapy-associated symptoms and osteoarthritis, with the quality of that evidence stated per indication. Concerns dietary supplements rather than culinary ginger.
Guideline: Sodium intake for adults and children
Governmenthigh reliabilityWorld Health Organization · 2012
A systematic-review-based guideline on dietary sodium and its relationship to blood pressure and cardiovascular risk. Competent for the sodium–blood-pressure relationship, which is dietary rather than medicinal exposure and is therefore one of the very few health findings in this dataset that concerns the amounts people actually eat. It is about sodium, not about salt as a seasoning ingredient, and says nothing about the form salt is sold in.
Handbook of Herbs and Spices
Bookhigh reliabilityK. V. Peter (ed.) · Woodhead Publishing
Production, processing, grading and quality of individual spices across multiple volumes.
ISO/TC 34/SC 7 — Spices, culinary herbs and condiments
Standards bodyhigh reliabilityInternational Organization for Standardization
International standards for the specification, sampling and testing of spices, including grading schemes such as ISO 3632 for saffron.
LiverTox: Clinical and Research Information on Drug-Induced Liver Injury
Governmenthigh reliabilityNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health · 2025
Peer-reviewed records of hepatotoxicity associated with drugs and herbal products, each carrying an explicit likelihood score. Authoritative on whether a substance is an established cause of liver injury; it does not assess efficacy, and its records concern supplements rather than food.
Major food allergens under FALCPA and the FASTER Act (Food Allergen Labeling and Consumer Protection Act 2004; Food Allergy Safety, Treatment, Education and Research Act 2021)
Governmenthigh reliabilityUnited States Food and Drug Administration
The nine major food allergens requiring declaration in the United States: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and — since 1 January 2023 — sesame. Competent for the United States labelling position. Note that it does not designate celery or mustard, which the EU does, so the two jurisdictions genuinely differ on two ingredients in this catalogue.
Note on Capsicums
Historical primary sourcehigh reliabilityWilbur L. Scoville · Journal of the American Pharmaceutical Association · 1912
The original organoleptic dilution test that gives the Scoville scale its name. Modern figures are derived from HPLC measurement of capsaicinoids and converted, not from tasting panels.
On Food and Cooking: The Science and Lore of the Kitchen
Food sciencehigh reliabilityHarold McGee · Scribner · 2004
Food chemistry and the behaviour of aroma compounds during preparation and cooking. A secondary synthesis, not primary research.
ISBN 9780684800011
Opinion on glycyrrhizinic acid and its ammonium salt
Governmenthigh reliabilityScientific Committee on Food, European Commission · 2003
Toxicological assessment of glycyrrhizinic acid, the sweet compound of liquorice root, covering the mineralocorticoid effects — raised blood pressure and lowered potassium — observed with sustained intake, and the wide variation in individual susceptibility. Competent for the existence and mechanism of the effect and for the fact that habitual consumers are the population at issue. It concerns the compound and liquorice confectionery rather than occasional culinary use of the root.
https://food.ec.europa.eu/system/files/2020-12/sci-com_scf_out186_en.pdf
Peppermint Oil: Usefulness and Safety
clinical-guidancehigh reliabilityNational Center for Complementary and Integrative Health, National Institutes of Health
Clinical evidence for peppermint oil, principally in irritable bowel syndrome, with the quality of the evidence stated per indication. Its subject throughout is peppermint oil in enteric-coated capsules — a pharmaceutical preparation designed to reach the intestine intact — and it states no position on peppermint leaf, peppermint tea or mint as a culinary herb.
Plants of the World Online
Botanical databasehigh reliabilityRoyal Botanic Gardens, Kew
Accepted botanical names, synonymy, family placement and native distribution. Not a source for culinary, sensory or commercial information.
PubChem compound database
Reference workhigh reliabilityNational Center for Biotechnology Information, US National Library of Medicine
Molecular identity: formulae, structures, isomer relationships and synonyms for individual compounds. Competent for what a molecule is and for whether two names denote the same substance. Not a source for sensory character, culinary behaviour, dose response or safety, and it aggregates depositor-supplied records whose annotations vary in quality.
Public statement on the use of herbal medicinal products containing estragole
Governmenthigh reliabilityEuropean Medicines Agency, Committee on Herbal Medicinal Products (HMPC)
Regulatory assessment of estragole exposure from herbal preparations, including fennel. Concerns concentrated preparations and sustained medicinal use; it does not establish a hazard from culinary quantities of fennel seed, and must not be cited as though it does.
Questions and Answers on Monosodium Glutamate (MSG)
Governmenthigh reliabilityUnited States Food and Drug Administration
The regulatory position on monosodium glutamate: its generally-recognised-as-safe status, the labelling requirement, and the agency’s summary of the evidence on reported short-term reactions. Competent for the regulatory status and for the state of the evidence on the reported symptom complex. It is not a source for glutamate biochemistry or for culinary use.
https://www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg
Regulation (EC) No 1334/2008 on flavourings and certain food ingredients with flavouring properties
Governmenthigh reliabilityEuropean Parliament and Council of the European Union · 2008
Sets maximum levels for certain substances of toxicological concern — including myristicin — in compound foodstuffs to which flavourings or food ingredients with flavouring properties have been added. Competent for the existence and regulatory treatment of those substances; it is not a clinical source and states no dose-response for whole spices.
Regulation (EU) No 1169/2011 on the provision of food information to consumers, Annex II
Governmenthigh reliabilityEuropean Parliament and Council of the European Union · 2011
Annex II lists the fourteen substances and products that must be declared as allergens on food sold in the EU and Northern Ireland. Three are relevant to this catalogue: celery, mustard and sesame seeds. Competent for what must be declared and for nothing else — it is a labelling instrument, not a clinical one, and absence from Annex II is not a statement that no one is allergic to a substance.
Safrole, and sassafras bark and oil, prohibited from use in food (21 CFR 189.180)
Governmenthigh reliabilityUnited States Food and Drug Administration · 1960
The regulatory prohibition on safrole and on sassafras bark and oil as food ingredients, following carcinogenicity findings in animals. Competent for what is and is not permitted, and specifically relevant to the distinction between sassafras root bark and the leaf: the leaf carries far less safrole, and ground sassafras leaf sold as file powder is not covered by the prohibition.
https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-189
Salt Toxicosis in Animals
veterinaryhigh reliabilityMSD Veterinary Manual
Sodium ion intoxication in animals, its dependence on water availability, and reported acute lethal doses. Relevant to heavily salted human food given to a pet; not a source about spices generally.
https://www.msdvetmanual.com/toxicology/salt-toxicosis/salt-toxicosis-in-animals
Scientific Opinion on the risks for public health related to the presence of opium alkaloids in poppy seeds
Governmenthigh reliabilityEuropean Food Safety Authority, CONTAM Panel · 2011
Assessment of morphine and related alkaloids present on poppy seeds as a result of contamination from the plant during harvest, rather than from the seed itself. Competent for the origin of the alkaloids, for the large variation between batches and between processing methods, and for the fact that washing and heat treatment substantially reduce them. It is not a source on workplace drug testing policy.
Spice: The History of a Temptation
Bookmedium reliabilityJack Turner · Alfred A. Knopf · 2004
Narrative history of European demand for spices. Popular history: useful for context and for identifying disputed claims, weaker as a primary authority.
ISBN 9780375407215
Tonka beans and tonka bean extracts prohibited from use in food (21 CFR 189.130)
Governmenthigh reliabilityUnited States Food and Drug Administration
The United States prohibition on tonka bean and tonka bean extract as food ingredients, on account of their coumarin content. Competent for what is and is not permitted in the United States, and for nothing else: it states no dose response, and the European position on coumarin is a limit rather than a prohibition, so the two must not be read as one rule.
https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-189
Turmeric means 'yellow' in Bengali: Lead chromate pigments added to turmeric threaten public health across Bangladesh
Academic paperhigh reliabilityJenna E. Forsyth, et al. · Environmental Research · 2019
Documented lead chromate adulteration of turmeric in specific supply chains. Evidence is specific to the regions studied and should not be generalised to all turmeric.
Turmeric: Usefulness and Safety
clinical-guidancehigh reliabilityNational Center for Complementary and Integrative Health, National Institutes of Health · 2025
A US government summary of the clinical evidence for turmeric and curcumin, and of the reported harms. Its subject is the supplement literature: it assesses concentrated and bioavailability-enhanced preparations, and states no position on turmeric used as a seasoning.