Editing Talc (section)

==Uses==
[[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.

Due to its low shear strength, talc is one of the oldest known solid lubricants. Also, limited use is made of talc 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 used in the production of the materials that are widely used in the building interiors such as base content [[paint]]s in wall coatings. Other areas that use talc to a great extent are organic [[agriculture]], the food industry, cosmetics, and hygiene products such as baby powder and [[Laundry detergent|detergent powder]].

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}}</ref>