{{Short description|Cleaning agent for motor vehicles}} {{more citations needed|date=February 2019}}
right|thumb|Brake cleaner in different containers '''Brake cleaner''' is a mostly colorless cleaning agent, designed for cleaning brake dust from the brake disks and other components of motor vehicles. It is also frequently used for cleaning other parts including the engine compartment as a general ''parts cleaner'', although this is not a recommended use case by most manufacturers. An important feature is that the brake cleaner leaves no residue after the solvents evaporate.<ref name="bghm">''[http://www.bghm.de/fileadmin/user_upload/Arbeitsschuetzer/Praxishilfen/Fachbereichs-Informationsblaetter/048_MO_E2010-06_Exschutz-KFZ-Reiniger.pdf Explosionsschutz beim Umgang mit brennbaren Reinigern in der Kfz-Werkstatt (PDF; 762 kB).]''</ref>
== Composition == Chlorinated brake cleaners (often sold as non-flammable)<ref name=CRC1>{{cite web |url=https://www.crcindustries.com/products/brakleen-174-pro-series-brake-parts-cleaner-non-flammable-29-wt-oz-05089PS.html |title=Brakleen® Pro-Series Brake Parts Cleaner - Non-Flammable, 29 Wt Oz |accessdate=22 November 2020 |publisher=CRC Industries |website=crcindustries.com}}</ref> use organochlorides like tetrachloroethylene and dichloromethane.<ref>{{cite web |title=Brakleen® Brake Parts Cleaner, 55 Gal |url=https://www.crcindustries.com/products/brakleen-174-brake-parts-cleaner-55-gal-05093.html |website=Main Website Store |accessdate=2 July 2019 |language=en}}</ref><ref>{{cite web |title=Berryman Brake Parts Cleaner SDS |url=https://www.berrymanproducts.com/assets/5C-4-aerosol-1420-SDS.pdf |website=berrymanproducts.com |access-date=12 January 2021}}</ref> Historically 1,1,1-trichloroethane was used, sometimes together with tetrachloroethylene. It was phased out because of its ozone-depleting nature.<ref>{{cite book |last1=Morrison |first1=Robert D. |last2=Murphy |first2=Brian L. |title=Chlorinated Solvents: A Forensic Evaluation |date=9 November 2015 |url=https://books.google.com/books?id=YGwoDwAAQBAJ&pg=PT89 |accessdate=2 July 2019 |publisher=Royal Society of Chemistry |language=en|isbn=9781782626077 }}</ref>
Non-chlorinated brake cleaners use hydrocarbons as a main component; it will either be a low-boiling aliphatic compound or higher-boiling hydrocarbon mixture. Aromatics like benzene, toluene or xylene may also be used.<ref>{{cite web |title=SAFETY DATA SHEET Brakleen® Brake Parts Cleaner |url=http://docs.crcindustries.com/msds/1003704E.pdf |website=crcindustries.com |accessdate=3 July 2019}}</ref> The hydrocarbons used are sometimes made by hydrogenation from naphtha. The lipophilic liquids dissolve fat-soluble lubricants or oils. Some products also contain polar solvents such as ethanol,<ref>http://docs.crcindustries.com/msds/5151.pdf Brakleen® Brake Parts Cleaner Safety Data Sheet</ref> methanol,<ref>https://www.safety-kleen.com/sites/g/files/bdczcs371/files/2019-05/820076Brev12-16.pdf SAFETY-KLEEN PROFESSIONAL BRAKE CLEANER - <45% VOC - Bulk Safety Data Sheet</ref> isopropanol, and acetone in order to dissolve non-lipophilic substances. Many formulations are incompatible with various materials, especially plastics.
== Use == The main application of brake cleaners is the degreasing and cleaning of metal parts or metallic surfaces. They are used for removing oils, fats, resins, tar and dust, mainly in motor vehicles.
About 10 million liters are consumed per year in Germany.<ref name="bghm"/>
== Danger == Brake cleaners contain toxic compounds and should be used only in well-ventilated areas or outdoors. Some are highly flammable and harmful for the environment, which also has to be considered during storage. Skin exposure to the solvent mixture may cause irritation and defatting injury. Chlorinated brake cleaners contain chlorinated hydrocarbons, which can produce the highly toxic gas phosgene when exposed to high heat or open flame, such as when welding metal parts that have been cleaned with them.<ref>{{Cite web |title=Phosgene {{!}} Medical Management Guidelines {{!}} Toxic Substance Portal {{!}} ATSDR |url=https://wwwn.cdc.gov/tsp/MMG/MMGDetails.aspx?mmgid=1201&toxid=182 |access-date=2025-12-16 |website=wwwn.cdc.gov}}</ref>
Brake cleaners decompose rubber and some types of plastics by removing binding components. The rubber appears unchanged at first; however, it will become brittle, and after a few weeks to months cracks and fractures appear.
== Alternatives == For frequent and industrial use, cleaning and degreasing may be replaced by supercritical carbon dioxide or dry-ice blasting, which is abrasive. This requires a setup to apply the carbon dioxide. While the harmful vapors are eliminated, the CO<sub>2</sub> must be ventilated. Applying the carbon dioxide causes electrostatic discharge by the expanding gas. The dust and harmful brake dust is not bound in the liquid.
== References == <references />
Category:Cleaning products Category:Vehicle braking technologies Category:Pages with unreviewed translations