View source for Talc

{{Short description|Phyllosilicate mineral in the pyrophyllite-talc group}}
{{Redirect|Talcum|other uses|Talcum (disambiguation)|and|TALC (disambiguation){{!}}TALC}}
{{Redirect|Magnesium silicate|the synthetic form|synthetic magnesium silicate|Mg<sub>2</sub>SiO<sub>4</sub>|forsterite|MgSiO<sub>3</sub>|enstatite|}}
{{Use dmy dates|date=October 2020}}
{{Infobox mineral
| name = Talc 
| category = [[Phyllosilicate]] [[minerals]], pyrophyllite-talc [[Mineral group|group]]
| boxwidth =
| boxbgcolor =#aad595
| image=   Talc-177589.jpg
| imagesize  = 250px
| caption = 
| formula = {{chem2|Mg3Si4O10(OH)2}}
| IMAsymbol   = Tlc<ref>{{cite journal |last=Warr|first=L. N. |date=2021 |title=IMA–CNMNC approved mineral symbols |journal=[[Mineralogical Magazine]] |volume=85 |issue=3 |pages=291–320 |doi=10.1180/mgm.2021.43 |bibcode=2021MinM...85..291W |s2cid=235729616 |doi-access=free}}</ref>
| system = [[Monoclinic]] or [[triclinic]]<ref name="DHZ">{{cite book |title=[[An Introduction to the Rock-Forming Minerals]] |edition=2nd |editor1=W. A. Deer |editor1-link=William Alexander Deer |editor2=R. A. Howie |editor3=J. Zussman |year=1992 |publisher=[[Prentice Hall]] |isbn=0-582-30094-0}}</ref>
| class = Either prismatic (2m) or pinacoidal ({{overline|1}})<ref name=Handbook/>
| symmetry = ''C2/c'' or ''C{{overline|1}}''
| unit cell = a = 5.291&nbsp;[[Ångström|Å]], b = 9.173&nbsp;Å<br />c = 5.290&nbsp;Å; α = 98.68°<br />β = 119.90°, γ = 90.09°; Z&nbsp;=&nbsp;2 or<br />a = 5.287&nbsp;Å, b = 9.158&nbsp;Å<br />c = 18.95&nbsp;[Å], β = 99.3°; Z&nbsp;=&nbsp;4<ref name=Handbook/>
| strunz = 9.EC.05
| color = [[shades of green|Light to dark green]], brown, white, grey, colorless
| habit = Foliated to fibrous masses, rare as platey to pyramidal crystals
| twinning =
| cleavage = Perfect on {001} [[cleavage (crystal)|basal cleavage]]
| fracture = Flat surfaces (not cleavage), fracture in an uneven pattern
| tenacity = [[sectility|Sectile]]
| mohs = 1 (defining mineral)
| luster = Waxy or pearly
| refractive = n<sub>α</sub> = 1.538 – 1.550<br />n<sub>β</sub> = 1.589 – 1.594<br />n<sub>γ</sub> = 1.589 – 1.600
| opticalprop = Biaxial (−)
| birefringence = δ = 0.051
| pleochroism = Weak in dark varieties
| streak = White jot to pearl black
| gravity = 2.58–2.83
| melt =
| fusibility =
| diagnostic =
| solubility =
| diaphaneity = Translucent
| fluorescence = Short UV: orange yellow; long UV: yellow
| references = <ref name=Handbook>{{cite book |editor1-last=Anthony|editor1-first=John W. |editor2-last=Bideaux|editor2-first=Richard A. |editor3-last=Bladh|editor3-first=Kenneth W. |editor4-last=Nichols|editor4-first=Monte C. |title=Handbook of Mineralogy |publisher=[[Mineralogical Society of America]] |location=[[Chantilly, Virginia]] |chapter-url=https://rruff.info/doclib/hom/talc.pdf |chapter=Talc |isbn=0-9622097-1-6 |volume=II (Silica, Silicates) |year=1995}}</ref><ref name=Mindat>{{Mindat |id=3875 |name=Talc}}</ref><ref name=Webmin>{{WebMineral |urk=https://webmineral.com/data/Talc.shtml |title=Talc Mineral Data}}</ref>
}}

'''Talc''', or '''talcum''', is a [[clay mineral]] [[chemical composition|composed]] of [[hydrate]]d [[magnesium]] [[silicate]], with the [[chemical formula]] {{chem2|Mg3Si4O10(OH)2}}. Talc in powdered form, often combined with [[corn starch]], is used as [[baby powder]]. This mineral is used as a [[thickening agent]] and [[lubricant]]. It is an ingredient in [[ceramic]]s, [[paint]]s, and [[roofing material]]. It is a main ingredient in many [[cosmetics]].<ref>{{cite web |title=Talc |url=https://mineralseducationcoalition.org/minerals-database/talc/ |website=Minerals Education Coalition}}</ref> It occurs as [[foliation (geology)|foliated]] to [[fiber|fibrous]] masses, and in an exceptionally rare [[crystal]] form. It has a perfect [[cleavage (crystal)|basal cleavage]] and an uneven flat fracture, and it is foliated with a two-dimensional [[ped|platy]] form.

The [[Mohs scale]] of mineral hardness, based on [[scratch hardness|scratch]] [[hardness comparison]], defines value 1 as the hardness of talc, the softest mineral. When scraped on a [[streak (mineralogy)|streak plate]], talc produces a white streak, though this indicator is of little importance, because most silicate minerals produce a white streak. Talc is translucent to opaque, with colors ranging from whitish grey to green with a vitreous and pearly [[Lustre (mineralogy)|luster]]. Talc is not soluble in water, and is slightly soluble in dilute [[mineral acid]]s.<ref>''Profiles of Drug Substances, Excipients and Related Methodology, Volume 36'' {{ISBN|978-0-123-87667-6}} p. 283</ref>

[[Soapstone]] is a [[metamorphic rock]] composed predominantly of talc.

==Etymology==
The word ''talc'' derives from {{langx|fa|تالک}} ''tālk''. In ancient times, the word was used for various related minerals, including talc, [[mica]], and [[selenite (mineral)|selenite]].<ref>{{OEtymD|talc}}</ref>

==Formation==
[[File:Talc block.jpg|thumb|right|A block of talc]]

Talc dominantly forms from the metamorphism of magnesian minerals such as [[Serpentine subgroup|serpentine]], [[pyroxene]], [[amphibole]], and [[olivine]], in the presence of carbon dioxide and water. This is known as "talc carbonation" or "steatization" and produces a suite of rocks known as [[talc carbonate]]s.{{citation needed|date=October 2025}}

Talc is primarily formed by hydration and carbonation by this reaction:

:{{overset|[[Serpentine subgroup|serpentine]]|2 Mg<sub>3</sub>Si<sub>2</sub>O<sub>5</sub>(OH)<sub>4</sub>}} + {{overset|[[carbon dioxide]]|3 CO<sub>2</sub>}} → {{overset|talc|Mg<sub>3</sub>Si<sub>4</sub>O<sub>10</sub>(OH)<sub>2</sub>}} + {{overset|[[magnesite]]|3 MgCO<sub>3</sub>}} + {{overset|[[water]]|3 H<sub>2</sub>O}}

Talc can also be formed via a reaction between dolomite and silica, which is typical of [[skarn]]ification of dolomites by silica-flooding in contact metamorphic aureoles:

:{{overset|[[Dolomite (mineral)|dolomite]]|3 CaMg(CO<sub>3</sub>)<sub>2</sub>}} + {{overset|[[Silicon dioxide|silica]]|4 SiO<sub>2</sub>}} + {{overset|water|H<sub>2</sub>O}} → {{overset|talc|Mg<sub>3</sub>Si<sub>4</sub>O<sub>10</sub>(OH)<sub>2</sub>}} + {{overset|[[calcite]]|3 CaCO<sub>3</sub>}} + {{overset|carbon dioxide|3 CO<sub>2</sub>}}

Talc can also be formed from magnesium chlorite and quartz in [[blueschist]] and [[eclogite]] metamorphism by the following [[metamorphic reaction]]:

:[[Chlorite group|chlorite]] + [[quartz]] → [[kyanite]] + talc + water

Talc is also found as a diagenetic mineral in sedimentary rocks where it can form from the transformation of metastable hydrated magnesium-clay precursors such as [[kerolite]], [[sepiolite]], or [[stevensite]] that can precipitate from marine and lake water in certain conditions.<ref name="Strauss MacDonald Halverson Tosca 2015 pp. 881–944">{{cite journal | last1=Strauss | first1=Justin V. | last2=MacDonald | first2=Francis A. | last3=Halverson | first3=Galen P. | last4=Tosca | first4=Nicholas J. | last5=Schrag | first5=Daniel P. | last6=Knoll | first6=Andrew H. | title=Stratigraphic evolution of the Neoproterozoic Callison Lake Formation: Linking the break-up of Rodinia to the Islay carbon isotope excursion | journal=American Journal of Science | publisher=American Journal of Science (AJS) | volume=315 | issue=10 | year=2015 | issn=0002-9599 | doi=10.2475/10.2015.01 | pages=881–944| bibcode=2015AmJS..315..881S | s2cid=130671089 | url=http://nrs.harvard.edu/urn-3:HUL.InstRepos:30367434 | doi-access=free }}</ref>

In this reaction, the ratio of talc and kyanite depends on [[aluminium]] content, with more aluminous rocks favoring production of kyanite. This is typically associated with high-pressure, low-temperature minerals such as [[phengite]], [[garnet]], and [[glaucophane]] within the lower [[Blueschist#Blueschist facies|blueschist facies]]. Such rocks are typically white, friable, and fibrous, and are known as
[[whiteschist]].{{citation needed|date=October 2025}}

Talc is a trioctahedral layered mineral; its structure is similar to [[pyrophyllite]], but with magnesium in the octahedral sites of the composite layers.<ref name="DHZ" /> The crystal structure of talc is described as ''TOT'', meaning that it is composed of parallel ''TOT'' layers weakly bonded to each other by weak [[van der Waals force]]s. The ''TOT'' layers in turn consist of two tetrahedral sheets (''T'') strongly bonded to the two faces of a single trioctahedral sheet (''O''). It is the weak bonding between ''TOT'' layers that gives talc its perfect basal cleavage and softness.<ref>{{cite book |last=Nesse |first=William D. |date=2000 |title=Introduction to mineralogy |location=New York |publisher=Oxford University Press |isbn=978-0-19-510691-6 |page=238}}</ref>

The tetrahedral sheets consist of silica tetrahedra, which are silicon ions surrounded by four oxygen ions. The tetrahedra each share three of their four oxygen ions with neighboring tetrahedra to produce a hexagonal sheet. The remaining oxygen ion (the ''apical'' oxygen ion) is available to bond with the trioctahedral sheet.{{sfn|Nesse|2000|p=235}}

The trioctahedral sheet has the structure of a sheet of the mineral [[brucite]]. Apical oxygens take the place of some of the hydroxyl ions that would be present in a brucite sheet, bonding the tetrahedral sheets tightly to the trioctahedral sheet.{{sfn|Nesse|2000|pp=235–237}}

Tetrahedral sheets have a negative charge, since their bulk composition is {{chem2|Si4O10(4-)}}. The trioctahedral sheet has an equal positive charge, since its bulk composition is {{chem2|Mg3(OH)2(4+)}} The combined TOT layer thus is electrically neutral.{{sfn|Nesse|2000|p=238}}

Because the hexagons in the T and O sheets are slightly different in size, the sheets are slightly distorted when they bond into a TOT layer. This breaks the hexagonal symmetry and reduces it to monoclinic or triclinic symmetry.{{sfn|Nesse|2000|pp=239, 242}} However, the original hexahedral symmetry is discernible in the pseudotrigonal character of talc crystals.<ref name=Handbook/>

<gallery>
File:Mica T.png|View of tetrahedral sheet structure of talc. The apical oxygen ions are tinted pink.
File:Talc to.jpg|View of trioctahedral sheet of talc. Yellow spheres are hydroxyl; blue are magnesium. Apical oxygen binding sites are white.
File:Talc structure.jpg|Talc crystal viewed along the [100] axis, looking along the layers of the crystal
</gallery>

==Occurrence==
{{more citations needed section|date=October 2025}}
[[File:2005talc.png|thumb|Talc output in 2005]]
[[File:Talc mine SLNSW FL20821008.jpg|thumb|Miners working a Talc mine (Tumby Bay?), Australia, c. 1950]]
Talc is a common metamorphic mineral in metamorphic belts that contain [[ultramafic rock]]s, such as [[soapstone]] (a high-talc rock), and within whiteschist and [[blueschist]] metamorphic [[terrane]]s. Prime examples of whiteschists include the Franciscan Metamorphic Belt of the western United States, the western European [[Alps]] especially in Italy, certain areas of the [[Musgrave Block]], and some collisional [[Orogeny|orogens]] such as the [[Himalayas]], which stretch along [[Pakistan]], [[India]], [[Nepal]], and [[Bhutan]].

[[Talc carbonate]] ultramafics are typical of many areas of the [[Archean|Archaean]] [[craton]]s, notably the [[komatiite]] belts of the [[Yilgarn craton]] in [[Western Australia]]. Talc-carbonate ultramafics are also known from the [[Lachlan Fold Belt]], eastern [[Australia]], from [[Brazil]], the [[Guiana Shield]], and from the [[ophiolite]] belts of [[Turkey]], [[Oman]], and the [[Middle East]].

China is the key world talc and steatite-producing country with an output of about 2.2&nbsp;million tonnes (2016), which accounts for 30% of total global output. The other major producers are Brazil (12%), India (11%), the U.S. (9%), France (6%), Finland (4%), Italy, Russia, Canada, and Austria (2%, each).<ref>{{cite web|title=China, Brazil, the U.S. and India Remain the Major Consumers on the Global Talc Market |url=https://www.indexbox.io/blog/china-brazil-the-u-s-and-india-remain-the-major-consumers-on-the-global-talc-market/ |website=IndexBox |date=18 July 2018 |first=Anna |last=Sergeeva}}</ref>

Notable economic talc occurrences include the Mount Seabrook talc mine, Western Australia, formed upon a polydeformed, layered ultramafic intrusion. The France-based [[Luzenac Group]] is the world's largest supplier of mined talc. Its largest talc mine at Trimouns near [[Luzenac]] in southern France produces 400,000&nbsp;tonnes of talc per year.

==Conflict mineral==
Extraction in disputed areas of [[Nangarhar province]], Afghanistan, has led the international monitoring group [[Global Witness]] to declare talc a [[conflict resource]], as the profits are used to fund armed confrontation between the [[Taliban]] and [[Islamic State of Iraq and the Levant|Islamic State]].<ref>{{cite web|title=Talc: the everyday mineral funding Afghan insurgents|url=https://www.globalwitness.org/en-gb/campaigns/afghanistan/talc-everyday-mineral-funding-afghan-insurgents/|website=Global Witness|access-date=24 May 2018|archive-date=24 May 2018|archive-url=https://web.archive.org/web/20180524222404/https://www.globalwitness.org/en-gb/campaigns/afghanistan/talc-everyday-mineral-funding-afghan-insurgents/}}</ref>

==Uses==
{{more citations needed section|date=October 2025}}
[[File:Talcum Powder.JPEG|thumb|Talcum powder]]
[[File:Talc.GIF|thumb|upright=1.3|The structure of talc is composed of Si<sub>2</sub>O<sub>5</sub> sheets with magnesium sandwiched between sheets in octahedral sites.]]
Talc is used in many industries, including paper making, [[plastic]], paint and coatings (e.g. for metal casting molds), rubber, food, electric cable, pharmaceuticals, cosmetics, and ceramics. A coarse grayish-green high-talc rock is [[soapstone]] or [[Soapstone|steatite]], used for stoves, sinks, electrical switchboards, etc. It is often used for surfaces of laboratory table tops and electrical switchboards because of its resistance to heat, electricity, and acids.

In finely ground form, talc finds use as a [[Cosmetics|cosmetic]] ('''talcum powder'''), as a [[lubricant]], and as a filler in paper manufacture. It is used to coat the insides of [[Tire#Associated components|inner tubes]] and rubber gloves during manufacture to keep the surfaces from sticking. Talcum powder, with heavy refinement, has been used in baby powder, an [[astringent]] powder used to prevent [[Irritant diaper dermatitis|diaper rash]] (nappy rash). The [[American Academy of Pediatrics]] recommends that parents avoid using baby powder because it poses a risk of respiratory problems, including breathing trouble and serious lung damage if inhaled. The small size of the particles makes it difficult to keep them out of the air while applying the powder. [[Zinc oxide]]-based ointments are a much safer alternative.<ref>{{usurped|1=[https://web.archive.org/web/20140901060623/http://www.babycenter.com/404_is-it-safe-to-use-baby-powder-on-my-baby_1519559.bc "Is it safe to use baby powder on my baby?"]}}. Babycenter.com (2017-05-01). Retrieved on 2017-05-06.</ref>

Soapstone (massive talc) is often used as a marker for [[welding]] or [[metalworking]].<ref>{{cite web |title=Why Do Welders Use Soapstone? |url=https://weldersmanual.com/why-do-welders-use-soapstone/ |website=Welders Manual |date=28 March 2021 |access-date=7 March 2022}}</ref><ref>{{cite web |last1=Young |first1=Pierre |title=What Is Soapstone Used for in Welding? |url=https://weldingheadquarters.com/what-is-soapstone-used-for-in-welding/ |website=Welding Headquarters |date=10 June 2020 |access-date=7 March 2022}}</ref>

Talc is also used as [[food additive]] or in pharmaceutical products as a [[glidant]]. In medicine, talc is used as a [[pleurodesis]] agent to prevent recurrent [[pleural effusion]] or [[pneumothorax]]. In the [[European Union]], the [[E number|additive number]] is '''E553b'''. Talc may be used in the processing of white [[rice]] as a buffing agent in the polishing stage.

Because of its low shear strength, talc is one of the oldest known solid lubricants. It also has some limited use as a friction-reducing additive in lubricating oils.<ref>{{cite journal|title=Talc as friction-reducing additive to lubricating oil|doi=10.1016/j.apsusc.2013.03.102|journal=Applied Surface Science|volume =276|year= 2013|pages =383–389|author1=Rudenko, Pavlo  |author2=Bandyopadhyay, Amit |bibcode=2013ApSS..276..383R}}</ref>

Talc is widely used in the ceramics industry in both bodies and glazes. In low-fire art-ware bodies, it imparts whiteness and increases thermal expansion to resist [[crazing]]. In [[stoneware]]s, small percentages of talc are used to flux the body and therefore improve strength and [[Glass transition|vitrification]]. It is a source of [[Magnesium oxide|MgO]] flux in high-temperature glazes (to control melting temperature). It is also employed as a matting agent in earthenware glazes and can be used to produce magnesia mattes at high temperatures.

ISO standard for quality (ISO 3262)

{| class="wikitable"
|-
! Type !! Talc content min. wt% !! Loss on ignition at 1000&nbsp;°C, wt % !! Solubility in HCl, max. wt %
|-
| A || 95 || 4–6.5 || 5
|-
| B || 90 || 4–9 || 10
|-
| C || 70 || 4–18 || 30
|-
| D || 50 || 4–27 || 30
|}

Patents are pending on the use of magnesium silicate as a cement substitute. Its production requirements are less energy-intensive than ordinary [[Portland cement]] (at a heating requirement of around 650&nbsp;°C for talc compared to 1,500&nbsp;°C for limestone to produce Portland cement), while it absorbs far more [[carbon dioxide]] as it hardens. This results in a negative [[carbon footprint]] overall, as the cement substitute removes 0.6 tonnes of CO<sub>2</sub> per tonne used. This contrasts with a positive carbon footprint of 0.4 tonnes per tonne of conventional cement.<ref name="guardian.co.uk">Jha, Alok (31 December 2008) [https://www.theguardian.com/environment/2008/dec/31/cement-carbon-emissions Revealed: The cement that eats carbon dioxide], ''The Guardian''</ref>

Talc is sometimes used as an [[adulterant]] to illegal [[heroin]], to expand volume and weight and thereby increase its street value. With [[Intravenous therapy|intravenous]] use, it may lead to [[pulmonary talcosis]], a [[granuloma]]tous inflammation in the [[lung]]s.

===Sterile talc powder===
Sterile talc powder ([[National Drug Code|NDC]] 63256-200-05) is a sclerosing agent used in the procedure of [[pleurodesis]]. This can be helpful as a [[Treatment of cancer|cancer treatment]] to prevent [[pleural effusion]]s (an abnormal collection of fluid in the space between the [[lung]]s and the [[thoracic wall]]). It is inserted into the space via a chest tube, causing it to close up, so fluid cannot collect there. The product can be sterilized by dry heat, [[ethylene oxide]], or [[Ionizing radiation sterilization|gamma irradiation]].<ref name="Management_of_Malignant_Pleural_Effusions">{{cite journal |title =Management of Malignant Pleural Effusions |journal = Am J Respir Crit Care Med |volume = 162 |issue = 5 |date = November 2000 |pmid = 11069845 |pages = 1987–2001 |url = https://www.atsjournals.org/doi/10.1164/ajrccm.162.5.ats8-00 |author= American Thoracic Society |doi = 10.1164/ajrccm.162.5.ats8-00|url-access = subscription }}</ref>

==Safety==
Suspicions have been raised that talc use contributes to certain types of disease, mainly cancers of the ovaries and lungs. According to the [[International Agency for Research on Cancer|IARC]], talc containing asbestos is classified as a [[IARC group 1|group 1 agent]] (carcinogenic to humans), talc use in the [[perineum]] is classified as [[IARC group 2B|group 2B]] (possibly carcinogenic to humans), and talc not containing asbestos is classified as [[IARC group 2A|group 2A]] (probably carcinogenic to humans).<ref>[http://monographs.iarc.fr/ENG/Classification/latest_classif.php List of Classifications] {{Webarchive|url=https://web.archive.org/web/20170610015529/http://monographs.iarc.fr/ENG/Classification/latest_classif.php |date=10 June 2017 }}, International Agency for Research on Cancer</ref> Reviews by [[Cancer Research UK]] and the [[American Cancer Society]] conclude that some studies have found a link, but other studies have not.<ref>[http://info.cancerresearchuk.org/healthyliving/cancercontroversies/talcum-powder/ Talcum powder and cancer] {{Webarchive|url=https://web.archive.org/web/20120815024743/http://info.cancerresearchuk.org/healthyliving/cancercontroversies/talcum-powder/ |date=15 August 2012 }}, Cancerresearch.uk</ref><ref>[http://www.cancer.org/Cancer/CancerCauses/OtherCarcinogens/AtHome/talcum-powder-and-cancer Talcum Powder and Cancer] {{Webarchive|url=https://web.archive.org/web/20161120023848/http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/talcum-powder-and-cancer |date=20 November 2016 }}, American Cancer Society</ref>

The studies discuss [[Lung|pulmonary]] issues,<ref>
{{cite journal
|pmid=2198684|title=Pulmonary toxicity of inhaled and intravenous talc|year=1990
|last1=Hollinger
|first1=MA
|volume=52
|issue=2
|pages=121–7; discussion 117–9
|journal=[[Toxicology Letters]]
|doi=10.1016/0378-4274(90)90145-C}}
</ref> [[lung cancer]],<ref name="NTP">
{{cite journal
|pmid=12616290
|url=https://ntp.niehs.nih.gov/publications/reports/tr/tr421
|title=NTP Toxicology and Carcinogenesis Studies of Talc (Non-Asbestiform) in Rats and Mice (Inhalation Studies)|year=1993
|last1=National Toxicology
|first1=Program
|volume=421
|pages=1–287
|journal=National Toxicology Program Technical Report Series}}</ref><ref>{{Cite web |date=1995 |title=Worker Health Study Summaries – Talc Miners & Millers |url=https://www.cdc.gov/niosh/pgms/worknotify/Talc.html |url-status=live |archive-url=https://web.archive.org/web/20220707125712/https://www.cdc.gov/niosh/pgms/worknotify/Talc.html |archive-date=2022-07-07 |access-date=2022-08-31 |website=The National Institute for Occupational Safety and Health (NIOSH)}}</ref> and [[ovarian cancer]].<ref>
{{cite journal|pmid=1603491|title=Perineal exposure to talc and ovarian cancer risk
|author=Harlow, Cramer, Bell|year=1992|volume=80|issue=1|pages=19–26|journal=Obstetrics and Gynecology|display-authors=etal}}</ref> One of these, published in 1993, was a US [[National Toxicology Program]] report, which found that cosmetic grade talc containing no [[asbestos]]-like fibres was correlated with tumor formation in [[rat]]s forced to inhale talc for 6 hours a day, five days a week over at least 113 weeks.<ref name="NTP" /> A 1971 paper found particles of talc embedded in 75% of the ovarian tumors studied.<ref>
{{cite journal
|pmid=5558843|title=Talc and carcinoma of the ovary and cervix|vauthors=Henderson WJ, Joslin CA, Turnbull AC, Griffiths K |year=1971
|journal=J Obstet Gynaecol Br Commonw|volume=78|issue=3|pages=266–272
|doi=10.1111/j.1471-0528.1971.tb00267.x|s2cid=32300387}}
</ref> In 2018, [[Health Canada]] issued a warning against inhaling talcum powder or women's using it perineally.<ref>{{Cite web|url=https://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2018/68320a-eng.php|title=Talc – Potential Risk of Lung Effects and Ovarian Cancer|date=19 November 2018}}</ref>

In contrast, however, research published in 1995 and 2000 concluded that, although it was plausible that talc could cause ovarian cancer, no conclusive evidence had been shown.<ref>{{cite journal|last1=Harlow|first1=BL|last2=Hartge|first2=PA|title=A review of perineal talc exposure and risk of ovarian cancer.|journal=[[Regulatory Toxicology and Pharmacology]] |date=Apr 1995|volume=21|issue=2|pages=254–60|pmid=7644715|doi=10.1006/rtph.1995.1039|url=https://zenodo.org/record/1229955}}</ref><ref>{{cite journal|last1=Gertig|first1=D. M.|last2=Hunter|first2=D. J.|last3=Cramer|first3=D. W.|last4=Colditz|first4=G. A.|last5=Speizer|first5=F. E.|author5-link=Frank E. Speizer|last6=Willett|first6=W. C.|last7=Hankinson|first7=S. E.|title=Prospective Study of Talc Use and Ovarian Cancer|journal=JNCI Journal of the National Cancer Institute|date=2 February 2000|volume=92|issue=3|pages=249–252|doi=10.1093/jnci/92.3.249|pmid=10655442|url=https://academic.oup.com/jnci/article-pdf/92/3/249/9996398/249.pdf}}</ref> Further, a 2008 [[European Journal of Cancer Prevention]] review of ovarian cancer and talc use studies pointed out that, although many of them examined the duration, frequency, and accumulation of hygienic talc use, few found a positive association among these factors and some found a negative one: "It may be argued that the overall null findings associated with talc-dusted diaphragms and condom use is more convincing evidence for a lack of a carcinogenic effect, especially given the lack of an established correlation between perineal dusting frequency and ovarian tissue talc concentrations and the lack of a consistent dose-response relationship with ovarian cancer risk." Instead, the authors credited powdered talc with "a high degree of safety."<ref>{{cite journal|last1=Muscat|first1=Joshua E.|last2=Huncharek|first2=Michael S.|title=Perineal Talc Use and Ovarian Cancer: A Critical Review|journal=European Journal of Cancer Prevention|date=April 2008|volume=17|issue=2|pages=139–146|doi=10.1097/CEJ.0b013e32811080ef|pmid=18287871|pmc=3621109}}</ref>

Similarly, in a 2014 article published in a leading cancer journal, the [[Journal of the National Cancer Institute]], researchers reported the results of a survey of 61,576 postmenopausal women, more than half of whom had used talc powder perineally. The researchers compared the subjects' reports of their own talc use with their reports of having had ovarian cancer diagnosed by their doctors, and found, regardless of subjects' age and tubal ligation status, "Ever use of perineal powder ... was not associated with risk of ovarian cancer compared with never use," nor was any greater individual cancer risk associated with longer use of talc powder. On this basis, the article concluded, "perineal powder use does not appear to influence ovarian cancer risk."<ref>{{cite journal|last1=Houghton|first1=Serena C.|last2=Reeves|first2=Katherine W.|last3=Hankinson|first3=Susan E.|last4=Crawford|first4=Lori|last5=Lane|first5=Dorothy|last6=Wactawski-Wende|first6=Jean|last7=Thomson|first7=Cynthia A.|last8=Ockene|first8=Judith K.|title=Perineal Powder Use and Risk of Ovarian Cancer|journal=JNCI Journal of the National Cancer Institute|date=11 September 2014|volume=106|issue=9|article-number=dju208 |doi=10.1093/jnci/dju208|pmid=25214560|url=https://academic.oup.com/jnci/article/106/9/dju208/910075|pmc=4200058}}</ref> The [[Cosmetic Ingredient Review|Cosmetic Ingredient Review Expert Panel]] concluded in 2015 that talc, in the concentrations currently used in cosmetics, is safe.<ref>{{cite journal |last1=Gruber |first1=James |title=Do Cosmetic Consumers Really Know What Ingredients They Are Using? An Inquiry into the Search for the 'Truth' |journal=Skeptical Inquirer |date=November–December 2019 |volume=43 |issue=6 |page=54}}</ref>

In July 2024, the [[International Agency for Research on Cancer]] listed talc as "probably" [[carcinogen]]ic for humans. The study is based on limited evidence it could cause [[ovarian cancer]] in humans.<ref>{{cite news |last1= |first1= |title=WHO agency says talc is 'probably' cancer-causing|url=https://globalnation.inquirer.net/241682/who-agency-says-talc-is-probably-cancer-causing |access-date=July 7, 2024 |publisher= [[Philippine Daily Inquirer]]|date=July 6, 2024}}</ref>{{better source needed|reason= Unlike other layperson medical reporting sites (e.g., Medical Xpress), this article does not provide a link to the WHO publication for verification. A second source doing so would be very useful.|date=January 2025}}

===Industrial grade===
In the United States, the [[Occupational Safety and Health Administration]] and [[National Institute for Occupational Safety and Health]] have set occupational exposure limits to respirable talc dusts at 2&nbsp;mg/m<sup>3</sup> over an eight-hour workday. At levels of 1000&nbsp;mg/m<sup>3</sup>, inhalation of talc is considered [[immediately dangerous to life and health]].<ref>
{{cite web|title = NIOSH Pocket Guide to Chemical Hazards|publisher = Centers for Disease Control and Prevention|year=2011|url = https://www.cdc.gov/niosh/npg/npgd0584.html}}</ref>

===Food grade===
The United States [[Food and Drug Administration]] considers talc (magnesium silicate) [[generally recognized as safe]] (GRAS) to use as an [[anticaking agent]] in table salt in concentrations smaller than 2%.<ref>
{{cite web
|title = Code of Federal Regulations
|publisher = U.S. Food and Drug Administration|year=2009
|url = https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.2437}}
</ref>

===Association with asbestos===
One particular issue with commercial use of talc is its frequent co-location in underground deposits with [[asbestos]] ore. Asbestos is a general term for different types of fibrous silicate minerals, desirable in construction for their heat resistant properties.<ref>{{cite web |title=Asbestos |url=https://mineralseducationcoalition.org/minerals-database/asbestos/ |website=Minerals Education Coalition}}</ref> There are six varieties of asbestos; the most common variety in manufacturing, [[white asbestos]], is in the [[serpentine subgroup|serpentine]] family.<ref>{{cite book |last1=Plummer |first1=Charles C. |last2=Carlson |first2=Diane H. |last3=Hammersley |first3=Lisa |title=Physical Geology |isbn=978-1-260-09165-6 |edition=Sixteenth|date=22 January 2018 |publisher=McGraw-Hill Education }}</ref> Serpentine minerals are [[sheet silicate]]s; although not in the serpentine family, talc is also a sheet silicate, with two sheets connected by magnesium cations. The frequent co-location of talc deposits with asbestos may result in contamination of mined talc with white asbestos, which poses serious health risks when dispersed into the air and inhaled. Stringent quality control since 1976, including separating [[cosmetic-grade|cosmetic-]] and [[food-grade]] talc from that destined for industrial use, has largely eliminated this issue, but it remains a potential hazard requiring mitigation in the mining and processing of talc.<ref>{{cite news |title=Is talcum powder asbestos? |url=https://www.straightdope.com/columns/read/996/is-talcum-powder-asbestos/ |website=[[The Straight Dope]] |date=16 February 1990 |access-date=9 March 2019}}</ref> A 2010 US [[FDA]] survey failed to find asbestos in a variety of talc-containing products.<ref>
{{cite web
|title = Talc Ingredients
|publisher = U.S. Food and Drug Administration|year=2010
|url = https://www.fda.gov/cosmetics/cosmetic-ingredients/talc}}</ref> A 2018 [[Reuters]] investigation asserted that pharmaceuticals company [[Johnson & Johnson]] knew for decades that there was asbestos in its baby powder,<ref>{{Cite news|url=https://www.reuters.com/investigates/special-report/johnsonandjohnson-cancer/|title=J&J knew for decades that asbestos lurked in its Baby Powder|work=Reuters|language=en|access-date=2018-12-15}}</ref> and in 2020 the company stopped selling its baby powder in the US and Canada.<ref>{{cite news |title=Johnson & Johnson stops selling baby powder in US |url=https://www.bbc.co.uk/news/business-52732755 |access-date=20 May 2020 |work=BBC News |date=20 May 2020}}</ref> There were calls for Johnson & Johnson's largest shareholders to force the company to end global sales of baby powder, and hire an independent firm to conduct a racial justice audit as it had been marketed to African American and overweight women.<ref>{{Cite news |title=Johnson & Johnson shareholders called on to end talc baby powder sales |last=Perkins |first=Tom |newspaper=The Guardian |date=27 April 2022 |url= https://www.theguardian.com/business/2022/apr/27/johnson-and-johnson-baby-powder-talc-shareholders}}</ref> On August 11, 2022, the company announced it would stop making talc-based powder by 2023 and replace it with cornstarch-based powders. The company said the talc-based powder is safe to use and does not contain asbestos.<ref>{{cite news|url=https://www.bbc.com/news/business-62514263 | title=J&J to replace talc-based powder with cornstarch after cancer lawsuits | date=August 12, 2022 | publisher=BBC News  |access-date=August 12, 2022 }}</ref>

==Litigation==

In 2006 the [[International Agency for Research on Cancer]] classified talcum powder as a possible human carcinogen if used in the female genital area. Despite this, no federal agency in the US acted to remove talcum powder from the market or add warnings.<ref>{{cite news|url=https://www.nytimes.com/2017/08/22/health/417-million-awarded-in-suit-tying-johnsons-baby-powder-to-cancer.html|title=$417 Million Awarded in Suit Tying Johnson's Baby Powder to Cancer|newspaper=The New York Times|date=22 August 2017|access-date=13 July 2018|last1=Rabin|first1=Roni Caryn}}</ref>

In February 2016, as the result of a lawsuit against [[Johnson & Johnson]] (J&J), a [[St. Louis]] jury awarded $72 million to the family of an Alabama woman who died from [[ovarian cancer]]. The family claimed that the use of talcum powder was responsible for her cancer.

In May 2016, a South Dakota woman was awarded $55 million as the result of another lawsuit against J&J.<ref>{{cite web|url=https://money.cnn.com/2016/05/03/news/companies/johnson-and-johnson-cancer-talcum-powder/index.html|title=Johnson & Johnson just lost another talcum powder cancer lawsuit|last=McLean|first=Rob|date=2016-05-03|website=CNNMoney|access-date=2016-08-18}}</ref> The woman had used Johnson & Johnson's [[Baby Powder]] for more than 35 years before being diagnosed with ovarian cancer in 2011.<ref>{{Cite web|title=Professor Hanington's Speaking of Science: Does talc cause cancer?|url=https://elkodaily.com/lifestyles/professor-haningtons-speaking-of-science-does-talc-cause-cancer/article_74d2eef7-6c68-504e-8c46-8c41898b2884.html|access-date=2021-03-09|website=Elko Daily Free Press|date=15 October 2016 |language=en}}</ref>

In October 2016, a St. Louis jury awarded $70.1 million to a Californian woman with ovarian cancer who had used Johnson's Baby Powder for 45 years.<ref name="latimes-2016-10-28">[http://www.latimes.com/business/la-fi-baby-powder-cancer-20161028-story.html#nt=oft07a-2gp1 Does baby powder cause cancer? Another jury thinks so, awarding $70 million to a California woman]. ''[[LA Times]]'' (2016-10-28). Retrieved on 2017-05-06.</ref>

In August 2017, a Los Angeles jury awarded $417 million to a Californian woman, Eva Echeverria, who developed ovarian cancer as a  "proximate result of the unreasonably dangerous and defective nature of talcum powder", her lawsuit against Johnson & Johnson stated.<ref>[http://thechronicleherald.ca/business/1496091-jury-awards-417m-in-lawsuit-linking-talcum-powder-to-cancer Jury awards $417M in lawsuit linking talcum powder to cancer]. The Chronicle Herald (21 August 2017)</ref> On 20 October 2017, [[Los Angeles Superior Court]] judge Maren Nelson dismissed the verdict. The judge stated that Echeverria proved there is "an ongoing debate in the scientific and medical community about whether talc more probably than not causes ovarian cancer and thus (gives) rise to a duty to warn", but not enough to sustain the jury's imposition of liability against Johnson & Johnson stated, and concluded that Echeverria did not adequately establish that talc causes ovarian cancer.<ref>{{cite news|url=https://www.reuters.com/article/us-johnson-johnson-cancer-lawsuit/california-judge-tosses-417-million-talc-cancer-verdict-against-johnson-johnson-idUSKBN1CQ003|title=California judge tosses $417 million talc cancer verdict against...|first=Tina|last=Bellon|work=Reuters|date=21 October 2017|access-date=13 July 2018}}</ref><ref>{{cite news|url=https://www.reuters.com/article/frankel-jj-talc/dismissal-of-472-million-verdict-v-jj-is-disaster-for-talc-plaintiffs-idUSKBN1CS2SA|title=Dismissal of $417 million verdict v. J&J is disaster for talc...|first=Alison|last=Frankel|work=Reuters|date=24 October 2017|access-date=13 July 2018}}</ref>

In July 2018, a court in [[St. Louis]] awarded a $4.7bn claim ($4.14bn in punitive damages and $550m in compensatory damages) against J&J to 22 claimant women, concluding that the company had suppressed evidence of [[asbestos]] in its products for more than four decades.<ref>{{cite news|url=https://www.theguardian.com/business/2018/jul/13/johnson-johnson-ordered-to-pay-47bn-in-talc-powder-claim|title=Johnson & Johnson ordered to pay $4.7bn in talc powder claim|first=Sarah|last=Butler|date=13 July 2018|newspaper=[[The Guardian]]|access-date=13 July 2018}}</ref>

At least 1,200 to 2,000 other talcum powder-related lawsuits were pending {{As of|2016|lc=y}}.<ref name="latimes-2016-10-28" /><ref>[http://www.nydailynews.com/life-style/health/woman-wins-55m-verdict-johnson-johnson-cancer-suit-article-1.2623470 Woman wins $55M verdict against Johnson & Johnson in cancer suit]. NY Daily News (3 May 2016)</ref>

In 2020 J&J stopped sales of its talcum-based baby powder, which it had been selling for 130 years. J&J created a subsidiary responsible for the claims in an effort to resolve the lawsuits in bankruptcy court. In 2023 J&J proposed a nearly $9bn settlement with 50,000 claimants saying the claims were "specious" but it wanted to move on from the issue, but judges blocked the plans, ruling that the subsidiary was not in financial distress and could not use the bankruptcy system to resolve the lawsuits.<ref>{{Cite news |date=2024-01-23 |title=J&J strikes US states deal over baby powder claims |url=https://www.bbc.com/news/business-68072951 |access-date=2024-04-14 |work=BBC News |language=en-GB}}</ref>

In July 2023 J&J sued researchers who linked talc to cancer, alleging they used [[junk science]] to disparage the company's products, while defendants say the lawsuits are meant to silence scientists.<ref>{{Cite news |last=Knauth |first=Dietrich |date=2023-07-13 |title=Johnson & Johnson sues researchers who linked talc to cancer |language=en |work=Reuters |url=https://www.reuters.com/legal/litigation/johnson-johnson-sues-researchers-who-linked-talc-cancer-2023-07-13/ |access-date=2023-07-17}}</ref>

==See also==
* {{Annotated link|Pyrophyllite}}
* {{Annotated link|Serpentinite}}
* {{Annotated link|Sillimanite}}

==References==
{{Reflist}}

{{commons category|Talc}}
{{wiktionary}}
{{Phyllosilicates}}
{{Mohs}}{{Clay minerals}}{{Antacids}}

{{Authority control}}

[[Category:Magnesium minerals]]
[[Category:Symbols of Vermont]]
[[Category:Cosmetics chemicals]]
[[Category:Excipients]]
[[Category:IARC Group 2A carcinogens]]
[[Category:Clay minerals group]]
[[Category:Triclinic minerals]]
[[Category:Minerals in space group 2]]
[[Category:Monoclinic minerals]]
[[Category:Minerals in space group 15]]
[[Category:Luminescent minerals]]
[[Category:E-number additives]]
[[Category:Pyrophyllite-Talc group]]