Is ACS only a numbered citation style?

No. The ACS Guide to Scholarly Communication (§4.3.2) defines three in-text systems: superscript numbers, italic numbers in parentheses, and author–date. Most ACS journals use superscripts. The journal or instructor chooses one system; you do not mix them.

Is the year or the volume bold in ACS?

The year is bold. The volume is italic. A bold volume and an italic year is a formatting error. The issue number, when present, is roman and sits in parentheses after the volume.

Should ACS journal titles be abbreviated?

Follow the venue. The current ACS Style Quick Guide examples often use full titles. Many chemistry departments still require CASSI abbreviations. One-word titles are never abbreviated. Look up every abbreviation in CASSI (database last updated 13 September 2026); do not invent one.

Do I still need an access date for a website or database?

Not by default. The April 2025 ACS Guide update says access dates for URL-based sources are no longer required. Some instructors still want one for a page that changes; add it when the assignment says so. A DOI already identifies a journal article. The Quick Guide still keeps an access date on the ChatGPT, GitHub, Wikipedia, and some website examples because those objects are not recoverable from a DOI alone.

How do I cite an ASAP ACS article once pages exist?

The Quick Guide's teaching line for Cheng et al., Journal of Natural Products 2025, still says ASAP Article and DOI 10.1021/acs.jnatprod.4c01436. Crossref now reports volume 88, issue 2, pages 554–562. If you read the paginated PDF, replace ASAP Article with 88 (2), 554–562. Do not keep both lines.

How do I cite Supporting Information?

Cite the article once. In the sentence, point the reader to the SI ("see the Supporting Information for the 1H NMR spectra"). Do not create a second reference for the SI PDF unless the journal's author guidelines ask for one.

How do I cite a CAS Registry Number, a PubChem record, a spectrum, or a dataset?

For a compound record, lead with the substance name, then the PubChem CID and/or CAS RN, then the database and the organization. The Quick Guide's Rotenone, SDBS, and Caffeine/Bio-Rad examples are the pattern. For reused files, cite the repository record as a dataset (Cappa et al. on Dryad; Xiang et al. on Zenodo). Cite RCSB PDB when the deposit is the object. Do not cite SciFinder when the object is a journal PDF you opened from a search.

How do I cite an SDS in ACS?

Use the product name, CAS RN, catalog or revision number, supplier, date, and URL. The Quick Guide example is 1,4'-Bipiperidine from Alfa Aesar (B22028, rev. 1, 27 March 2024). Cite the sheet you retrieved, not a generic hazard summary. Current ACS book examples omit the city for ACS, RSC, Wiley, and Springer; the 2006 "Hoboken, NJ" pattern is leftover.

Who wrote Steeped: The Chemistry of Tea in ACS examples?

The open Quick Guide currently prints Frankel, F. for that RSC 2024 book. The RSC title page and DOI 10.1039/9781837670383 name Michelle Francl. Cite the author on the copy you used. Do not treat the table-row surname as more authoritative than the title page.

How many authors does ACS list before et al.?

ACS lists the first 10 authors, then et al. Include every name when there are 10 or fewer. Do not carry an APA 20-author cutoff or an MLA three-author cutoff into an ACS list. Journal of Chemical Education is an ACS Publications journal; neighboring education-research titles such as Journal of Research in Science Teaching use APA—see ACS vs APA.

How to Cite Chemistry Sources in ACS Style (ACS Guide) [2026]

Quick Answer: How to Cite Chemistry Sources in ACS

Use one ACS in-text system for the whole document. Most ACS journals and many lab reports want superscript numbers after the punctuation. Some courses want italic numbers on the line so citations do not collide with compound 1. A few syllabi want author–date. Numbered lists follow first mention and reuse the original number; author–date lists are alphabetical. A journal reference puts authors first (surname, initials, semicolons), then the article title, the journal (full title or a CASSI abbreviation), a bold year, an italic volume, the issue if you have it, pages or an article number, and DOI: 10.….

ACS chemistry templates

Journal article:

Author, A. A.; Author, B. B. Title of article. Journal Title Year, volume (issue), pages. DOI: 10.xxxx/xxxxx

ASAP article (only while it is the file you read):

Author, A. A. Title of article. Journal Title Year, ASAP Article. DOI: 10.xxxx/xxxxx

Book:

Author, A. A. Title of Book, nth ed.; Publisher, Year.

Patent:

Inventor, A. A.; Inventor, B. B. Title of Patent. CountryCodeNumber, Year.

Database record:

Substance name (CAS RN: xx-xx-x). Database. Organization. https://xxxxx

Dataset:

Author, A. A. Title of Dataset (Dataset). Repository, Date. DOI: 10.xxxx/xxxxx

Superscript in text:

The coupling proceeds in one step.¹

Italic number in text:

The coupling proceeds in one step (1).

Author–date in text:

The coupling proceeds in one step (Tan et al., 2022).

The Quick Guide states the assumption behind every online example on this page. The date in the first sentence is the stamp on the open chapter, not a guess:

ACS Style Quick Guide §4.3.3 (open chapter stamp)

(Last Updated: April 8, 2025) Unless noted otherwise, the source type is online in all examples shown.

Articles (scientific journals, preprints, magazines, and newspapers) and books are listed first, with all other sources following in alphabetical order.

What this guide covers—and what it does not

Use this page when the hard part is the chemistry object: a JACS paper versus its Supporting Information, an ASAP manuscript versus the version of record, a CAS Registry Number versus SciFinder, an SDS versus a lecture slide about the hazard, a ChemRxiv version versus the later journal article, a Dryad dataset versus the paper that used it, or a PDB deposit versus the article that solved the structure. For the venue-first choice between ACS and APA, including chemistry-education journals, use ACS vs APA or the compact APA vs ACS table. For a one-source walkthrough, see how to cite a journal article in ACS or how to cite a patent in ACS. Nearby numbered styles are not ACS: biology citation covers CSE; RSC journals have their own author guidelines.

The current ACS authority is not a fourth-edition Style Guide

Departments still say "ACS style." They mean The ACS Guide to Scholarly Communication, the 2020 online successor to the printed ACS Style Guide, 3rd edition (2006). There is no current printed "ACS Style Guide, 4th edition." References live in chapter 4.3. The Quick Guide is §4.3.3; citation elements are §4.3.4; source templates are §4.3.5. ACS Publications points submitting authors to that guide for style, nomenclature, units, and what editors look for. If you are writing for J. Am. Chem. Soc., Org. Lett., or Anal. Chem., you also inherit ACS conventions for compound numbering, spectroscopic listings, and Supporting Information.

Spring 2025 updates, announced on the official ACS Axial channel on 9 May 2025, simplified student-facing rules. Two of those changes overturn advice still circulating on older lab-report handouts:

ACS Axial, 9 May 2025, announcing April 2025 updates to ACS Guide §4.3

Access dates for URL-based sources are no longer required.

DOI hyperlinks are now required to improve efficiency.

The same 2025 note relaxed article-title capitalization, allowed full journal titles or CASSI abbreviations, dropped commas from patent numbers so USPTO, EPO, and JPO identifiers share one pattern, and expanded the Quick Guide with AI, datasets, software, and social-media examples. A later Axial post (Chi Wang, 5 May 2026) is the current annual-update note. It does not reprint a new Quick Guide date stamp. It does name two reference-adjacent changes:

ACS Axial, 5 May 2026, Additional Updates

ACS Style Quick Guide (Section 4.3.3): Updated book citation guidance makes the Quick Guide easier to follow and apply.

Chemistry Preprints (Section 1.6.1): Updated arXiv information reflects current preprint resources.

If a 2006 photocopied handout still demands [Online], a city for Wiley, and an access date on every DOI, it is teaching the old book. If a later blog says the Quick Guide was last updated 14 April 2026, it is not reading the open chapter: the stamp on the page opened for this rewrite is 8 April 2025.

Choose one of the three ACS in-text systems

ACS is not "superscripts only." Section 4.3.2 lets the journal or instructor choose one marker. Superscripts are the default in most ACS journals. Italic parenthetical numbers keep citations from colliding with compound 1 or equation (1). Author–date is legal ACS; it is uncommon in ACS journals and common in courses that want names visible. Pick one system and keep it.

The three ACS in-text systems in ACS Guide §4.3.2
System	In-text marker	Reference-list order	Where you see it
Superscript numbers	after punctuation: the intermediate is a radical.^1,3	Numerical, by first mention	Most ACS journals and many lab reports
Italic numbers in parentheses	on the line: the intermediate is a radical (1, 3).	Numerical, by first mention	Journals that must distinguish citations from equation or compound numbers
Author–date	(Tan et al., 2022) or Tan et al. (2022)	Alphabetical by first author	Some courses; rare in ACS journals

Numbered ACS reuses the original number every time the source returns. A range of three or more consecutive numbers may close with an en dash (^1-3); non-consecutive numbers are comma-separated without spaces in superscript (^1,3,5) and with spaces on the line (1, 3, 5). If you name authors in the sentence, two authors take "and"; three or more take the first name plus "et al." with no comma before et al. Two authors in an author–date parenthesis still use "and," not an ampersand: (Tan and Glorius, 2022). In the reference list, ACS names the first 10 authors, then et al. UC San Diego's ACS names page, written by Quick Guide lead author Teri Vogel, restates the cutoff: if there are more than 10 authors, "et al" follows the 10th author.

Format the ACS list after the system is locked

The generator cannot choose superscripts versus author–date for you. Lock the in-text system from the syllabus or author guidelines, then format complete records.

Open the ACS citation generator →ACS style overview →

Journal articles

The Quick Guide's lead journal example is Tan, Das, Keum, Bellotti, Daniliuc, and Glorius, Nature Chemistry 2022, 14, 1174–1184. Article titles in the current examples are sentence case. The year is bold. The volume is italic. The issue sits in roman parentheses after a space. The DOI keeps the DOI: label. Italics below mark the journal and the volume; they are teaching markup, not extra punctuation.

ACS numbered reference (Quick Guide §4.3.3)

1. Tan, G. Y.; Das, M.; Keum, H.; Bellotti, P.; Daniliuc, C.; Glorius, F. Photochemical single-step synthesis of β-amino acid derivatives from alkenes and (hetero)arenes. Nature Chemistry 2022, 14 (10), 1174−1184. DOI: 10.1038/s41557-022-01008-w

Article numbers, subtitles, one-word titles, and classic papers

Some journals paginate by article number instead of a page span. One-word titles (Science, Nature, Langmuir, Biochemistry) are never abbreviated. The Quick Guide shows both cases, plus a subtitle after a colon. The Woodward–Hoffmann review is a real 1969 paper students already meet in organic chemistry; it is not a Quick Guide example, so the journal title is written in full rather than guessed from CASSI.

Official Quick Guide variants, then one verified classic

Article number (Westermayr et al., 2021):

Westermayr, J.; Gastegger, M.; Schütt, K. T.; Maurer, R. J. Perspective on integrating machine learning into computational chemistry and materials science. Journal of Chemical Physics 2021, 154 (23), 230903. DOI: 10.1063/5.0047760

Subtitle (Yang et al., 2020):

Yang, J. T.; Zhou, Y.; Guo, Q. L.; Dedkov, Y.; Voloshina, E. Electronic, magnetic and optical properties of MnPX3 (X = S, Se) monolayers with and without chalcogen defects: A first-principles study. RSC Advances 2020, 10 (2), 851−864. DOI: 10.1039/C9RA09030D

One-word journal (Hanikel et al., 2021):

Hanikel, N.; Pei, X. K.; Chheda, S.; Lyu, H.; Jeong, W.; Sauer, J.; Gagliardi, L.; Yaghi, O. M. Evolution of water structures in metal-organic frameworks for improved atmospheric water harvesting. Science 2021, 374 (6566), 454−459. DOI: 10.1126/science.abj0890

Classic review (not a Quick Guide example):

Woodward, R. B.; Hoffmann, R. The Conservation of Orbital Symmetry. Angewandte Chemie International Edition in English 1969, 8 (11), 781−853. DOI: 10.1002/anie.196907811

ASAP articles are not the version of record

ACS and other houses post articles as ASAP (As Soon As Publishable) before volume, issue, and final pages exist. Cite the ASAP record only if that is the file you read. The Quick Guide keeps the words ASAP Article in place of pagination. When the version of record appears, replace the ASAP line with the volume, issue, and pages. Do not keep both lines for the same paper.

Journal article early publication (Quick Guide §4.3.3) and the later recoverable record

Official ASAP line still printed in the Quick Guide:

Cheng, S.; Xu, Y.; Kang, M.; Zhu, W.; Wang, L.; Fu, P. Aurovertins from a Marine-Derived Penicillium Species and Nonenzymatic Reactions in Their Formation. Journal of Natural Products 2025, ASAP Article. DOI: 10.1021/acs.jnatprod.4c01436

Same DOI after issue assignment (Crossref, 28 February 2025 print issue):

Crossref now reports volume 88, issue 2, pages 554–562, online 25 January 2025 and in the 28 February 2025 print issue. The open Quick Guide has not replaced its ASAP teaching line. If you read the paginated PDF, cite the paginated line. If you only have the ASAP file, keep ASAP Article. Do not invent a third hybrid.

Journal titles: full name or CASSI, never a guess

Current Quick Guide examples often print the journal in full. Many chemistry departments still require the CASSI Search Tool. CAS describes that tool in one sentence, and the public database was last updated 13 September 2026:

CAS, About the CASSI Search Tool

The CASSI Search Tool is a complimentary resource that can be used to quickly and easily look up or confirm publication titles and abbreviations in an accessible electronic format.

The database was last updated September 13, 2026.

If the title is missing from CASSI, use the full title. Do not invent JACS or J. A. C. S. in the reference list; the CASSI form is J. Am. Chem. Soc. Angew. Chem., Int. Ed. includes the comma. Pick full titles or CASSI abbreviations and keep the choice consistent. For a DOI you do not have, use how to find a DOI.

Aggregator records, non-English titles, and translations

Opening a PDF from SciFinder, Web of Science, or ProQuest does not make the database the publisher. When the Quick Guide does want the aggregator named, it keeps the journal line and adds a retrieved-from note. Non-English titles stay in the original language. A translation and its original article can share one numbered reference.

Official Quick Guide journal variants students skip

Journal article from an aggregator:

Lynch, P.; Hasbrouck, C.; Wilck, J.; Kay, M.; Manogharan, G. Challenges and opportunities to integrate the oldest and newest manufacturing processes: metal casting and additive manufacturing. Rapid Prototyping Journal 2020, 26 (6), 1145−1154 (retrieved from ProQuest Materials Science & Engineering Collection). DOI: 10.1108/RPJ-10-2019-0277

Non-English article title:

Timmermans, J. Recherches de stoechiométrie I. La chaleur de fusion des composés organiques. Bulletin des Sociétés Chimiques Belges 1935, 44 (1), 17−40. DOI: 10.1002/j.0037-9646.1935.tb00352.x

Translated article and original article:

Kulinkovich, O. G.; Sviridov, S. V.; Vasilevskii, D. A.; Savchenko, A. I.; Pritytskaya, T. S. Reaction of Alkylmagnesium Halides with Esters of Carboxylic-Acids in the Presence of Tetraisopropoxytitanium. Journal of Organic Chemistry of the USSR 1991, 27 (2), 250−253. Zhurnal Organicheskoi Khimii 1991, 27 (2), 294−298.

Preprints are not the later paper

Cite ChemRxiv, arXiv, or another preprint server only when that version is what you read. The Quick Guide keeps the version and the posted date. ACS Guide §1.6 treats preprints as a distinct communication form, not a draft of the later article. The 5 May 2026 Axial note updates arXiv information in §1.6.1; it does not turn a ChemRxiv file into the later journal paper. If the same work later appears in a journal, cite the journal for claims that appear there and the preprint only for material that never made the published record.

ChemRxiv preprint (Quick Guide §4.3.3)

Deysher, G.; Oh, J. A. S.; Chen, Y.-T.; Sayahpour, B.; Ham, S.-Y.; Cheng, D.; Ridley, P.; Cronk, A.; Lin, S. W.-H.; Qian, K.; Nguyen, L. H. B.; Jang, J.; Meng, Y. S. An Anode-Free Sodium All-Solid-State Battery, Ver. 1. ChemRxiv, November 23, 2023. DOI: 10.26434/chemrxiv-2023-tkcd9

C&EN, magazines, and newspapers are not journal articles

A C&EN feature, a Popular Mechanics story, or a newspaper report on click chemistry uses the magazine or newspaper template, not the scientific-journal line. The year is still bold for C&EN Global Enterprise. Do not invent a volume style that matches JACS when the object is a news feature. The Guardian crystals piece and the Washington Post click-chemistry report are the Quick Guide's newspaper models.

Magazine and newspaper (Quick Guide §4.3.3)

Magazine:

Patel, P. Mighty MXenes: Ready to roll. C&EN Global Enterprise 2024, 102 (9), 26−32. DOI: 10.1021/cen-10209-cover

Newspaper:

Demming, A. 'Doing something for the real world': How 1,000 UK schoolkids helped crack a crystals conundrum. Guardian, March 2, 2024. https://www.theguardian.com/science/2024/mar/02/doing-something-for-the-real-world-how-1000-uk-schoolkids-helped-crack-a-crystals-conundrum

Newspaper from an aggregator:

Johnson, M. Nobel Prize awarded to three scientists for work in click chemistry, which links molecules quickly. Washington Post, October 5, 2022 (retrieved from ProQuest U.S. Major Dailies).

Books, chapters, and handbooks

Current ACS book examples omit place of publication for major houses (ACS, RSC, Wiley, Springer). The old "Wiley: Hoboken, NJ" pattern is leftover from the 2006 ACS Style Guide. Edition information stays after the title and is not italic. UC San Diego's book page, aligned with the 2026 Quick Guide book-citation refresh, says print books are cited the same as ebooks but without a DOI or URL, and that in most cases you can leave out the publisher location. Chapters in an authored book omit "In"; chapters in an edited collection keep the editor line. Handbook and encyclopedia lines often lead with the substance and the CAS Registry Number, not the editor.

Official ACS book, chapter, and handbook examples

Print book as the Quick Guide currently prints it:

Frankel, F. Steeped: The Chemistry of Tea; Royal Society of Chemistry, 2024.

Same book from the RSC title page (Michelle Francl):

Francl, M. Steeped: The Chemistry of Tea; Royal Society of Chemistry, 2024.

Book with edition (Atkins, 2024; official line has no DOI):

Atkins, P. Concepts in Physical Chemistry, 2nd ed.; Royal Society of Chemistry, 2024.

Same Atkins ebook if you used the RSC file:

Atkins, P. Concepts in Physical Chemistry, 2nd ed.; Royal Society of Chemistry, 2024. DOI: 10.1039/9781837674244

ACS ebook (Tanemura, Sierra-Costa, and Merz, 2022):

Tanemura, K. A.; Sierra-Costa, D.; Merz, K. M., Jr. Python for Chemists; American Chemical Society, 2022. DOI: 10.1021/acsinfocus.7e5030

Print book with edition (Berg et al., 2023):

Berg, J. M.; Gatto, G. J.; Hines, J. K.; Heller, J. B.; Tymoczko, J. L.; Stryer, L. Biochemistry, 10th ed.; Macmillan Learning, 2023.

Chapter in an authored book (Bard and Faulkner, 2022):

Bard, A. J.; Faulkner, L. R. Double-Layer Structure and Absorption. Electrochemical Methods: Fundamentals and Applications, 3rd ed.; Wiley, 2022; pp 599−652.

Book in a series (Hammond, 2015):

Hammond, C. The Basics of Crystallography and Diffraction, 4th ed.; International Union of Crystallography Texts on Crystallography, Vol. 21; Oxford University Press, 2015. DOI: 10.1093/acprof:oso/9780198738671.001.0001

Organization-authored handbook:

ACS Committee on Analytical Reagents. ACS Reagent Chemicals: Specifications and Procedures for Reagents and Standard-Grade Reference Materials, online ed.; Tyner, T., Francis, J., Eds.; American Chemical Society, 2024. DOI: 10.1021/acsreagents

CRC handbook line (Haynes, Lide, and Bruno, 2012):

Vanadium(V) Oxide (CAS RN: 1314-62-1). CRC Handbook of Chemistry and Physics, 93rd ed.; Haynes, W. M., Lide, D. R., Bruno, T. J., Eds.; CRC Press, 2012; Section 4, p 98.

CRC 104th-edition table (Rumble, 2023):

Environmental Chemistry Data (Section 10): Global Warming Potential of Greenhouse Gases. CRC Handbook of Chemistry and Physics, 104th ed.; Rumble, J. R., Ed.; CRC Press, 2023. https://hbcp.chemnetbase.com/

e-EROS reagent monograph:

Banfi, L.; Narisano, E.; Riva, R.; Stiasni, N.; Hiersemann, M.; Yamada, T.; Tsubo, T. Sodium Borohydride, Ver. 3 (CAS RN: 16940-66-2). e-EROS: Encyclopedia of Reagents for Organic Synthesis; Fuchs, P. L., Ed.; Wiley, 2014. DOI: 10.1002/047084289X.rs052.pub3

Two book-line traps sit in the official set. The open Quick Guide currently prints "Frankel, F." for Steeped: The Chemistry of Tea. The RSC book page and the copyright line name Michelle Francl (Bryn Mawr College). Cite the name on the title page you used; do not copy a swapped surname because a table row did. The Quick Guide's Atkins edition line has no DOI; the RSC ebook DOI 10.1039/9781837674244 is real if that file is what you read. The 104th CRC edition is a different editorship. The Quick Guide's 104th-edition table example names Rumble, J. R., as editor, not Haynes. If you used the 104th edition, cite that edition and that editor.

Patents

ACS patents use the issuing authority's document number without inserted commas. The Quick Guide example is the Baltimore small-RNA patent. The application is a different document with a different number. How to cite a patent in ACS walks the same template.

Patent and application (Quick Guide §4.3.3)

Granted patent:

Lois-Caballe, C.; Baltimore, D.; Qin, X.-F. Method for Expression of Small RNA Molecules within a Cell. US7732193B2, 2010.

Patent application:

Lois-Caballe, C.; Baltimore, D.; Qin, X.-F. Method for Expression of Small RNA Molecules within a Cell. US2003/0068821A1, 2003.

Finding a spectrum in SciFinder, Reaxys, or PubChem does not make SciFinder the source. ACS data citations lead with the substance name and the identifier the database uses, then name the database and the organization that publishes it. CAS Registry Numbers belong in ACS; they are not optional decoration. When SciFinder is only displaying a spectrum another lab deposited, the Quick Guide names that provider in parentheses.

Choose the ACS template from the object you used.
What you used	Cite this object	Do not cite
A journal PDF opened from SciFinder or Web of Science	The journal article, with its DOI	SciFinder, CAS, or Clarivate as the publisher
A PubChem compound record	The substance, PubChem CID, and CAS RN	"NCBI website" with no compound identity
A SciFinder IR spectrum supplied by Bio-Rad	The substance, CAS RN, SciFinder, and the provider note	"SciFinder" with no compound or spectrum ID
An SDBS NMR or IR spectrum	The substance, CAS RN, and SDBSWeb	A screenshot filename
A PDB or CSD deposit	The repository record (RCSB PDB in the Quick Guide)	Only the journal article that later discussed the structure
A CRC table	The table heading, edition, editors, section, and page	"CRC handbook" with no edition
A Dryad or Zenodo dataset	The dataset record, version, and repository DOI	Only the journal article that later used the files
Supporting Information for an ACS paper	The article; name the SI in the sentence	A second reference for the ZIP file

Official ACS database, spectrum, and structure citations

PubChem (Rotenone):

Rotenone (PubChem CID: 6758, CAS RN: 83-79-4). PubChem. U.S. Department of Health and Human Services, National Library of Medicine, National Center for Biotechnology Information. https://pubchem.ncbi.nlm.nih.gov/compound/6758

SDBS spectrum:

4-Bromo-2-fluorotoluene (CAS RN: 51436-99-8). SDBSWeb. National Institute of Advanced Industrial Science and Technology. https://sdbs.db.aist.go.jp/CompoundView.aspx?sdbsno=19589

SciFinder spectrum supplied by Bio-Rad:

Caffeine (CAS RN: 58-08-2). SciFinder. CAS. https://scifinder-n.cas.org(IR spectrum ID BR001206, provided by Bio-Rad Laboratories)

SpectraBase (the database, not one compound):

SpectraBase. Bio-Rad Laboratories. https://spectrabase.com/

Structure repository:

Research Collaboratory for Structural Bioinformatics. RCSB Protein Data Bank. https://www.rcsb.org/

Merck Index monograph:

Trazodone (CAS RN: 19794-93-5). The Merck Index Online. Royal Society of Chemistry. https://merckindex.rsc.org/monographs/m11010

Datasets are not the paper that used them

The April 2025 Quick Guide expansion added standalone dataset examples. Cite the repository record when the files are what you reused, even if a journal article later analyzed them. Keep the word (Dataset), the version if the repository gives one, and the dataset DOI. When the Quick Guide points at a companion article, it does so in a parenthetical after the dataset DOI—not by substituting the article for the data.

Datasets (Quick Guide §4.3.3)

Dataset without article (Cappa, Li, and Smith, 2018):

Cappa, C.; Li, Z.; Smith, K. Influence of Relative Humidity on the Heterogeneous Oxidation of Secondary Organic Aerosol (Dataset). Dryad, May 18, 2018. DOI: 10.25338/B8ZK5X

Dataset with article (Xiang et al., 2020):

Xiang, B.; Ribeiro, R. F.; Du, M.; Liying, C.; Yang, Z.; Wang, J.; Yuen-Zhou, J.; Xiong, W. Intermolecular Vibrational Energy Transfer Enabled by Microcavity Strong Light-Matter Coupling (Dataset), Ver 1. Zenodo, 2020. DOI: 10.5281/zenodo.3695870(data for Xiang et al. DOI: 10.1126/science.aba3544)

Safety data sheets and laboratory safety documents

Lab courses that ask for an SDS citation want the current ACS SDS template, not a 2006 MSDS photocopy and not a Wikipedia hazard box. The Quick Guide includes the product name, CAS RN, catalog or revision, supplier, date, and URL. Cite the sheet you opened. ACS also publishes standalone safety guidance you can cite as a website document when that is the object you used.

SDS and ACS safety document (Quick Guide §4.3.3)

Safety data sheet:

1,4'-Bipiperidine, 99% (CAS RN: 4897-50-1). B22028, rev. 1; Alfa Aesar, Thermo Fisher Scientific: Wood Hill, MA, March 27, 2024. https://www.thermofisher.com/order/catalog/product/B22028.14

ACS safety guidelines PDF:

Guidelines for Chemical Laboratory Safety in Academic Institutions. American Chemical Society, Committee on Chemical Safety, Task Force for Safety Education Guidelines, 2016. https://www.acs.org/content/dam/acsorg/about/governance/committees/chemicalsafety/publications/acs-safety-guidelines-academic.pdf

Software, code, and generative AI

Cite the computational chemistry program, the crystal-structure package, or the drawing tool you actually ran. The Quick Guide's software pattern is the product name, a version, and the publisher or a URL. Named scientific codes keep the author. A methods sentence still has to name the functional, basis set, or force field; the reference only identifies the program. Code that supplements a paper is a repository record, not a second copy of the article.

Software and code (Quick Guide §4.3.3)

Software with no named authors:

Mathematica, Ver. 14; Wolfram Research, 2024.

Software with authors:

Grossfield, A. WHAM: The Weighted Histogram Analysis Method, Ver. 2.0.11. http://membrane.urmc.rochester.edu/wordpress/?page_id=126

Software in GitHub:

Digital Science. Dimensions API Lab. https://github.com/digital-science/dimensions-api-lab(accessed 2024-05-21)

Code supplement for a journal article:

Parkinson, P.; Church, S. Code for: Holistic Determination of Optoelectronic Properties using High-Throughput Spectroscopy of Surface-Guided CsPbBr3 Nanowires. Figshare, May 11, 2022. DOI: 10.48420/19746757.v1(Code for Church; et al. 2022. https://arxiv.org/abs/2204.14065)

The Quick Guide now lists chatbot and image-generator formats. A reference is not enough. ACS says so in one sentence:

ACS Style Quick Guide, Artificial Intelligence

Researchers should check publisher guidelines on using and disclosing generative AI in manuscripts. Students should consult instructors on its permitted use and required disclosures in coursework.

However, such citations are no substitute for a more detailed disclosure within the work itself, including identification of prompts and the resulting generated content.

Suggested chatbot reference (Quick Guide; not a substitute for disclosure)

ChatGPT-4o (AI Chatbot). OpenAI. https://chatgpt.com/(accessed 2024-08-28)

Check the journal or instructor before you use a model at all. For the cross-style picture, see how to cite AI.

Theses, meetings, standards, and government reports

A dissertation is a recoverable document with a degree, an institution, and usually a handle or URL. ACS writes Ph.D. Dissertation or Ph.D. Thesis as the awarding university labels it, and M.S. Thesis for a master's file. A conference talk is a presentation, not a journal article, unless it later appeared in a proceedings volume. A special issue can be cited as a collection when you are pointing at the issue rather than one paper. ASTM and ISO methods are standards, not journal articles. A Federal Register notice, an NREL report, or a NASA technical memorandum uses the government or technical-report template.

Thesis, meeting, special issue, standard, and government (Quick Guide §4.3.3)

Dissertation:

Cable, M. L. Life in Extreme Environments: Lanthanide-Based Detection of Bacterial Spores and Other Sensor Design Pursuits. Ph.D. Dissertation, California Institute of Technology, 2010. http://resolver.caltech.edu/CaltechTHESIS:05102010-145436548

Print thesis:

Tsien, R. Y. The Design and Use of Organic Chemical Tools in Cellular Physiology. Ph.D. Thesis, University of Cambridge, 1976.

Master's thesis:

McGuire, B. A. High Resolution THz Spectroscopy of Astrophysically Relevant Ions. M.S. Thesis, Emory University, 2011. https://etd.library.emory.edu/concern/etds/9019s306w?locale=en

ACS meeting lecture:

Hammond, P. T. Sticky Particles for Health and Healing. Presented at the American Chemical Society National Meeting, Indianapolis, IN, March 28, 2023 (The Fred Kavli Innovations in Chemistry Lecture). https://www.acs.org/meetings/acs-meetings/past-meetings/kavli-lecture-series/sticky-particles-for-health-and-healing-2023.html

Special issue:

Research at HBCUs. Accounts of Chemical Research 2023, 56 (11), 1251−1357 (special issue). https://pubs.acs.org/page/achre4/research-at-hbcus

ASTM standard:

ASTM International. Standard Test Method for Tensile Properties of Plastics, ASTM D638-14; West Conshohocken, PA, 2014. DOI: 10.1520/D0638-14

Federal Register:

Environmental Protection Agency. Significant New Use Rules on Certain Chemical Substances. Federal Register 2019, 84 (53), 9999−10019. https://www.govinfo.gov/app/details/FR-2019-03-19/2019-04457y

NASA technical report:

Hung, C.-C.; Hurst, J.; Santiago, D. Boron Nitride Nanoribbons from Exfoliation of Boron Nitride Nanotubes, NASA/TM-2017-219455; National Aeronautics and Space Administration, Glenn Research Center: Cleveland, OH, 2017. https://ntrs.nasa.gov/search.jsp?R=2017000388

Websites, Wikipedia, protocols, and ACS videos

A lab homepage, a Compound Interest explainer, a protocols.io method, or an ACS Reactions YouTube video is not a journal article. The Quick Guide keeps the site or series as the container. Wikipedia is cited with a permanent oldid, not the live moving page. JoVE videos are the exception that look like journal articles.

Website, protocol, Wikipedia, and video (Quick Guide §4.3.3)

Website:

American Chemical Society. ACS Publications Home Page. https://pubs.acs.org/

Blog that is part of a larger work:

Brunning, A. National Tea Day: What causes the scum on tea? Compound Interest, April 23, 2023. https://www.compoundchem.com/2023/04/21/tea/

Method from protocols.io:

Gilpatrick, T.; Lee, I.; Graham, J. E.; Raimondeau, E.; Bowen, R.; Heron, A.; Sedlazeck, F. J.; Timp, W. Cas9 Enrichment for Nanopore Sequencing V.3. protocols.io; Springer Nature, September 22, 2020. https://www.protocols.io/view/cas9-enrichment-for-nanopore-sequencing-bmi5k4g6.pdf

Wikipedia (permanent oldid):

Oganesson. Wikipedia. https://en.wikipedia.org/w/index.php?title=Oganesson&oldid=1218419822(accessed 2024-04-21)

ACS Reactions YouTube video:

Conell, R.; Zamieroski, K.; Gentleman, D.; Waghorn, N.; Dylewski, A. Game of Thrones Science: Sword Making and Valyrian Steel. Reactions. American Chemical Society. YouTube, April 15, 2015. https://www.youtube.com/watch?v=cHRcGoje4j4

JoVE video (cited like a journal article):

Argyropoulos, D. S.; Pajer, N.; Crestini, C. Quantitative 31P NMR Analysis of Lignins and Tannins. Journal of Visualized Experiments 2021, 174, e62696. 10.3791/62696

If you are quoting a chemist's advice or an ACS accessibility post, cite that post. The Quick Guide keeps the platform, the date, and a URL when one exists. Do not turn a feed into a website homepage citation.

Social media (Quick Guide §4.3.3)

X (formerly Twitter):

Heemstra, J. (jenheemstra). If you’re choosing your PhD advisor, remember that the research you will do for the next 5 years is important, but even more important is finding the person who will be your mentor and champion throughout your career. You will never regret choosing a great mentor. #PhDchat. X (formerly Twitter), September 4, 2019. https://twitter.com/jenheemstra/status/1169218959977144320

Compound numbers, Supporting Information, and methods papers

ACS manuscripts number compounds in bold (1, 2a, 3) and number citations in a different series. A sentence can legally contain both: "Oxidation of 2 followed the protocol of Smith.⁴" Do not reuse a citation superscript as a compound number. Keep the compound scheme consistent from the experimental section through the SI.

Cite the original characterization. For a known compound, prefer the first synthesis or the paper that reported the spectra you compared, not the most recent paper that happened to use the molecule.
Cite the methods paper, not only the textbook. If you followed a published procedure, the experimental section should point at that article. Clayden or Atkins can still appear when you used the book as a book.
Treat Supporting Information as part of the article. Write "see the Supporting Information for the NMR spectra" and cite the paper once. Do not invent a second reference for si_001.pdf unless the venue asks for a separate SI citation.
Cite the ASAP file only while it is the file you read. When volume and pages appear, replace the ASAP line. Cheng et al. is the worked case: the Quick Guide still prints ASAP; Crossref now has 88 (2), 554–562.
Cite the dataset when you reused the files. A journal article that later analyzed the same deposit is a different object.
Cite the structure repository when the deposit is what you used. The Quick Guide's RCSB PDB line is a repository citation, not a substitute for the structure paper.
Record the full citation in the notebook when you run the reaction. Waiting until manuscript week is how invented titles and swapped page spans enter lab reports.
Do not cite a database for a journal article you opened as a PDF. The database is a finding tool. The article is the source.

RSC, Vancouver, and IEEE are cousins, not ACS

Royal Society of Chemistry journals, many Elsevier chemistry titles, and Vancouver-family medical journals also number citations. They are not ACS. RSC has its own author guidelines. Vancouver and AMA share a numbered medical tradition. If a supervisor says "just use numbered like JACS," confirm whether they mean ACS punctuation (semicolons between authors, bold year, DOI: 10.…) or merely a numeric marker. Chemistry departments that standardized on ACS still sit next to biology programs on CSE and medical programs on Vancouver; those maps live in citation styles by discipline and the chemistry field page.

Stay on this ACS page when

The journal is ACS Publications or the syllabus says ACS.
You must write a CAS RN, SDS, ChemRxiv version, ASAP line, dataset DOI, PDB deposit, or SI pointer.
The reader expects CASSI abbreviations or ACS compound numbering.
The claim is synthetic, analytical, physical, or computational chemistry.

Leave this page when

The venue is APA: education, psychology, or research on learning chemistry.
The journal is RSC or another house style that only looks numbered.
The paper is medical and the editor asked for Vancouver or AMA.
You still have not named the person who will accept the file.

Common mistakes in chemistry citations

Calling the current book "ACS Style Guide, 4th edition." The live manual is The ACS Guide to Scholarly Communication (2020). The last printed ACS Style Guide is the 3rd edition (2006).
Dating the open Quick Guide to 14 April 2026. The chapter stamp opened for this rewrite is 8 April 2025. The 5 May 2026 Axial post updates book-citation guidance; it does not reprint a new Quick Guide date.
Bold volume, italic year. ACS bolds the year and italicizes the volume. The reverse is a generator glitch, not an older ACS variant.
Inventing a journal abbreviation. Look it up in CASSI or write the title in full. JACS is informal.
Treating ACS as superscript-only. If the syllabus says author–date ACS, superscripts are the wrong system.
Writing roman `(1)` for an ACS parenthetical number. ACS on-the-line numbers are italic so they do not collide with compound 1.
Keeping a city on a Wiley, ACS, RSC, or Springer book. Current examples drop place of publication for those houses.
*Copying "Frankel, F." for Steeped without checking the title page.* RSC names Michelle Francl. Cite the author on the book you held.
Putting commas back into a patent number. The current form is US7732193B2, not U.S. Patent 11,234,567.
Citing SciFinder as the publisher of a journal article. Name the journal. Name SciFinder only when the object is a SciFinder record or a spectrum it provided.
Attaching Haynes to the 104th CRC Handbook. The Quick Guide's 104th-edition example is edited by Rumble.
Citing an ASAP article after pages exist. Cheng et al. now has 88 (2), 554–562. Replace the ASAP line if that is the file you read.
Substituting a journal article for a Dryad, Zenodo, or PDB deposit. Cite the repository record when the files or coordinates are what you used.
Giving an access date on every DOI. The 2025 update dropped required access dates for URL sources; a DOI already identifies the object.

Authoritative sources

Use these primary documents when a generator and a lab-report handout disagree. Secondary library guides are useful teaching aids; they are not the standard.

ACS Style Quick Guide (ACS Guide to Scholarly Communication §4.3.3; open chapter stamp 8 April 2025). Worked examples for articles, books, patents, data, theses, SDS files, software, government reports, Wikipedia, and AI.
ACS Axial, 9 May 2025 Guide updates. Official note that access dates are no longer required and DOI hyperlinks are required.
ACS Axial, 5 May 2026 Guide updates. Official note that §4.3.3 book-citation guidance and §1.6.1 arXiv information were revised.
CASSI Search Tool and CASSI About. Official journal-title abbreviations for chemistry; database last updated 13 September 2026.
UC San Diego ACS names and books pages (Teri Vogel and co-authors of the Quick Guide). Restate the 10-author cutoff and the 2026 book-location guidance.
ACS vs APA on this site, when the venue decision is still open.
Which citation style and citation styles by discipline, for the wider map.

Frequently Asked Questions

Is ACS only a numbered citation style?: No. The ACS Guide to Scholarly Communication (§4.3.2) defines three in-text systems: superscript numbers, italic numbers in parentheses, and author–date. Most ACS journals use superscripts. The journal or instructor chooses one system; you do not mix them.
Is the year or the volume bold in ACS?: The year is bold. The volume is italic. A bold volume and an italic year is a formatting error. The issue number, when present, is roman and sits in parentheses after the volume.
Should ACS journal titles be abbreviated?: Follow the venue. The current ACS Style Quick Guide examples often use full titles. Many chemistry departments still require CASSI abbreviations. One-word titles are never abbreviated. Look up every abbreviation in CASSI (database last updated 13 September 2026); do not invent one.
Do I still need an access date for a website or database?: Not by default. The April 2025 ACS Guide update says access dates for URL-based sources are no longer required. Some instructors still want one for a page that changes; add it when the assignment says so. A DOI already identifies a journal article. The Quick Guide still keeps an access date on the ChatGPT, GitHub, Wikipedia, and some website examples because those objects are not recoverable from a DOI alone.
How do I cite an ASAP ACS article once pages exist?: The Quick Guide's teaching line for Cheng et al., Journal of Natural Products 2025, still says ASAP Article and DOI 10.1021/acs.jnatprod.4c01436. Crossref now reports volume 88, issue 2, pages 554–562. If you read the paginated PDF, replace ASAP Article with 88 (2), 554–562. Do not keep both lines.
How do I cite Supporting Information?: Cite the article once. In the sentence, point the reader to the SI ("see the Supporting Information for the ¹H NMR spectra"). Do not create a second reference for the SI PDF unless the journal's author guidelines ask for one.
How do I cite a CAS Registry Number, a PubChem record, a spectrum, or a dataset?: For a compound record, lead with the substance name, then the PubChem CID and/or CAS RN, then the database and the organization. The Quick Guide's Rotenone, SDBS, and Caffeine/Bio-Rad examples are the pattern. For reused files, cite the repository record as a dataset (Cappa et al. on Dryad; Xiang et al. on Zenodo). Cite RCSB PDB when the deposit is the object. Do not cite SciFinder when the object is a journal PDF you opened from a search.
How do I cite an SDS in ACS?: Use the product name, CAS RN, catalog or revision number, supplier, date, and URL. The Quick Guide example is 1,4'-Bipiperidine from Alfa Aesar (B22028, rev. 1, 27 March 2024). Cite the sheet you retrieved, not a generic hazard summary. Current ACS book examples omit the city for ACS, RSC, Wiley, and Springer; the 2006 "Hoboken, NJ" pattern is leftover.
Who wrote Steeped: The Chemistry of Tea in ACS examples?: The open Quick Guide currently prints Frankel, F. for that RSC 2024 book. The RSC title page and DOI 10.1039/9781837670383 name Michelle Francl. Cite the author on the copy you used. Do not treat the table-row surname as more authoritative than the title page.
How many authors does ACS list before et al.?: ACS lists the first 10 authors, then et al. Include every name when there are 10 or fewer. Do not carry an APA 20-author cutoff or an MLA three-author cutoff into an ACS list. Journal of Chemical Education is an ACS Publications journal; neighboring education-research titles such as Journal of Research in Science Teaching use APA—see ACS vs APA.

Generate ACS citations from complete records

Lock the in-text system first. Then format journal articles, books, patents, datasets, and database records in ACS. A generator cannot invent an issue number, a CAS RN, an SDS revision, or a dataset version you never stored.

Try the ACS citation generator →