:HC-12a

{{Short description|Hydrocarbon blend used as a refrigerant}}

HC-12a, also called ES-12a, OZ-12a, DURACOOL 12a{{cite web |title=U.S. EPA: Legal Status of HC-12a®, DURACOOL 12a®, and OZ-12® |website=widit.knu.ac.kr |url=http://widit.knu.ac.kr/epa/ebtpages/Air/Air_Pollutants/Refrigerants/siteout/s4out9.html}} and Hydrocarbon Blend B, is marketed as a "drop-in" replacement refrigerant for R-12 and other refrigerants. HC-12a is a mixture of hydrocarbons, specifically propane (R-290) and isobutane (R-600a), and is therefore considered nearly non-ozone-depleting. The hydrocarbon blend is compatible with hoses and oils used in R-12 systems.

As it is flammable, it is illegal for use as an R-12 replacement in the United States.{{cite web |title=Unacceptable Substitute Refrigerants |website=United States Environmental Protection Agency |date=18 August 2016 |url=https://www.epa.gov/snap/unacceptable-substitute-refrigerants |access-date=20 March 2021 |url-status=live |archive-url=https://web.archive.org/web/20210227085943/https://www.epa.gov/snap/unacceptable-substitute-refrigerants |archive-date=27 February 2021}}{{cite web |title=SNAP Regulations |website=United States Environmental Protection Agency |date=11 December 2020 |url=https://www.epa.gov/snap/snap-regulations#self |url-status=dead |access-date=20 March 2021 |archive-url=https://web.archive.org/web/20210125050104/https://www.epa.gov/snap/snap-regulations |archive-date=25 January 2021 |quote=Unacceptable This designation means that it is illegal to use a product as a substitute for an ODS in a specific end-use.}} Its use in public transport vehicles has also been illegal in the United States since 1990.

This hydrocarbon blend caused{{cite web |title=Juicio en Estados Unidos por tragedia de la Cresta |url=https://www.laestrella.com.pa/panama/nacional/juicio-unidos-cresta-estados-tragedia-HMLE147264}} of the {{ill|Tragedia de La Cresta|2=es|3=Tragedia de La Cresta|preserve=1}} in October 2006,{{cite web |title=Llevan batalla legal a los tribunales estadounidenses |date=October 22, 2011 |website=Panamá América |url=https://www.panamaamerica.com.pa/nacion/llevan-batalla-legal-los-tribunales-estadounidenses-743269}} a bus fire which killed 18 people and injured 25, some severely, which in turn led to an overhaul of Panama City's public transport system.{{cite web |title=Recuerdan los 13 años de la tragedia del 8B-06 en la Cresta |date=23 October 2019 |url=https://www.tvn-2.com/nacionales/recuerdan-anos-tragedia-cresta-bus-incendio-octubre-video_1_1053850.html}}{{cite web |title=Vigilia por las víctimas del 8B-06 |url=https://www.laestrella.com.pa/panama/nacional/8b-06-vigilia-victimas-EMLE367120}}{{cite web |title=Papadimitriu: Nuevo sistema evitará tragedias como la Cresta |website=la Prensa Panamá |date=23 October 2009 |url=https://www.prensa.com/locales/Papadimitriu-Nuevo-sistema-tragedias-Cresta_0_2686981498.html}} The refrigerant ignited due to an electrical spark{{cite web |title=Corte en EU admite caso | la Prensa Panamá |date=24 April 2011 |url=https://www.prensa.com/politica/Corte-EU-admite-caso_0_3097940349.html}} which followed a refrigerant leak,{{cite web |title=La Cresta |date=9 July 2010 |url=https://www.panamaamerica.com.pa/opinion/la-cresta-576722}} which quickly set the bus ablaze as the fire spread from the refrigeration system towards the interior of the bus.https://www.prensa.com/sociedad/Autobus-infierno-grados-centigrados_0_4603789613.html, https://www.midiario.com/nacionales/luego-de-14-anos-de-la-tragedia-del-bus-8b-06-sobrevivientes-y-familiares-recuerdan-a-las-victimas-video/ (Both newspapers are owned by the same company, Corprensa: https://corprensa.com/nuestros-productos/){{cite web |title=La tragedia de la Cresta y el infierno del bus 8B-06 |url=https://elsiglo.com.pa/cronica-roja/tragedia-cresta-infierno-06-XHES24088743}}{{cite web |title=Empresa de Estados Unidos indemnizará a víctimas del bus 8B-06 | la Prensa Panamá |date=4 September 2018 |url=https://www.prensa.com/sociedad/Empresa-Unidos-indemnizara-victimas-bus_0_5114488536.html}} The bus lacked emergency exits and fire extinguishers, and the occupants' peril was aggravated by the location of the engine and the refrigeration system compressor—below a cover on the inner side of the only passenger exit door.{{cite web |title=¡Verdadero infierno! Sobreviviente del incendio del bus 8B-06 rompió silencio |date=23 October 2017 |url=https://www.midiario.com/panama/nacionales/verdadero-infierno-sobreviviente-del-incendio-del-bus-8b-06-rompio-silencio/}} A lawsuit in a US court against Northcutt, which imported the HC-12 involved in the tragedy, and OZ technology, Inc., which manufactured the HC-12{{cite web |title=Víctimas del bus 8B-06 logran acuerdo con empresa estadounidense para indemnización |date=3 September 2018 |url=https://ensegundos.com.pa/2018/09/03/victimas-del-bus-8b-06-logran-acuerdo-con-empresa-estadounidense-para-indemnizacion/}}{{cite web |title=Se cumplen 13 años de la Tragedia de la Cresta |date=23 October 2019 |url=https://ensegundos.com.pa/2019/10/23/se-cumplen-13-anos-de-la-tragedia-de-la-cresta/}}{{cite web |title=Víctimas de la tragedia de La Cresta fueron recordadas |website=metrolibre.com |url=https://www.metrolibre.com/nacionales/victimas-de-la-tragedia-de-la-cresta-fueron-recordadas-IFML152183}} began in 2008; in 2018, Northcutt reached a settlement with the victims of the tragedy and their relatives.{{cite web |title=Empresa estadounidense indemnizará a afectados de la tragedia del bus 8B-06 |date=3 September 2018 |url=https://www.panamaamerica.com.pa/sociedad/empresa-estadounidense-indemnizara-afectados-de-la-tragedia-del-bus-8b-06-1115153}}{{cite web |title=Se cumplen 14 años de la tragedia del Bus 8B-06 |date=23 October 2020 |url=https://www.telemetro.com/nacionales/2020/10/23/cumplen-14-anos-tragedia-bus/3379937.html}}