“Chloropicrin”的意思、由来-开放百科全书

Chloropicrin, also known as PS and nitrochloroform, is a chemical compound currently used as a broad-spectrum antimicrobial, fungicide, herbicide, insecticide, and nematicide.^[4] Its chemical structural formula is Cl₃CNO₂.

Synthesis

Chloropicrin was discovered in 1848 by Scottish chemist John Stenhouse. He prepared it by the reaction of sodium hypochlorite with picric acid:

Because of the precursor used, Stenhouse named the compound chloropicrin, although the two compounds are structurally dissimilar.

Today, chloropicrin is manufactured by the reaction of nitromethane with sodium hypochlorite:^[5]

Properties

Chloropicrin's chemical formula is CCl₃NO₂ and its molecular weight is 164.38 grams/mole.^[6] Pure chloropicrin is a colorless liquid, with a boiling point of 112 °C.^[6] Chloropicrin is sparingly soluble in water with solubility of 2000 mg/L at 25 °C.^[6] It is volatile, with a vapor pressure of 23.2 millimeters of mercury (mmHg) at 25 °C; the corresponding Henry's law constant is 0.00251 atmosphere-cubic meter per mole.^[6] The octanol-water partition coefficient (K_ow) of chloropicrin is estimated to be 269.^[6] Its soil adsorption coefficient (K_oc; normalized to soil organic matter content) is 25 cm³/g.^[6]

Use

Chloropicrin was manufactured for use as poison gas in World War I.^[7] In agriculture, chloropicrin is injected into soil prior to planting a crop in order to fumigate soil. Chloropicrin affects a broad spectrum of fungi, microbes, insects.^[8]^[9] It is commonly used as a stand-alone treatment or in combination / co-formulation with methyl bromide and 1,3-Dichloropropene.^[9]^[10]

Chloropicrin is used as an indicator and repellent while fumigating residences for insects with sulfuryl fluoride which is an odorless gas.^[11]

Safety

At the national level, chloropicrin is regulated by the United States Environmental Protection Agency as a restricted use pesticide.^[8]^[12] Because of its toxicity and carcinogenicity, distribution and use of chloropicrin is available only to licensed professionals and specially certified growers who are trained in its proper and safe use.^[8]^[12] In the US, occupational exposure limits have been set at 0.1 ppm over an eight-hour time-weighted average.^[13]

Agriculture

In 2008 the US EPA re-approved chloropicrin as safe for use in agricultural settings, stating that treatments "can provide benefits to both food consumers and growers. For consumers, it means more fresh fruits and vegetables can be cheaply produced domestically year-round because several severe pest problems can be efficiently controlled."^[14]^[15]^[16] To ensure chloropicrin is used safely, the EPA requires a strict set of protections for handlers, workers, and persons living and working in and around farmland during treatments.^[8]^[15] EPA protections were increased in both 2011 and 2012, reducing fumigant exposures and significantly improving safety.^[17] Protections include the training of certified applicators supervising pesticide application, the use of buffer zones, posting before and during pesticide application, fumigant management plans, and compliance assistance and assurance measures.^[16]^[18]

California

In California experience with acute effects of chloropicrin when used as a soil fumigant for strawberries and other crops led to the release of regulations in January 2015 creating buffer zones and other precautions to minimize exposure of farm workers, neighbors, and passersby.^[19]^[20]

High Concentrations

Chloropicrin is harmful to humans. It can be absorbed systemically through inhalation, ingestion, and the skin. At high concentrations it is severely irritating to the lungs, eyes, and skin.^[21] In World War I German forces used concentrated chloropicrin against Allied forces as a tear gas. While not as lethal as other chemical weapons, it caused vomiting and forced Allied soldiers to remove their masks to vomit, exposing them to other, more toxic chemical gases used as weapons during the war.^[22]

References

1. ^http://msds.chem.ox.ac.uk/CH/chloropicrin.html
2. ^¹²³⁴⁵{{PGCH|0132}}
3. ^¹{{IDLH|76062|Chloropicrin}}
4. ^{{cite web|title=RED Fact Sheet: Chloropicrin|url=http://www.epa.gov/oppsrrd1/REDs/factsheets/chloropicrin-fs.pdf|publisher=US Environmental Protection Agency|accessdate=20 September 2013|page=2|date=10 July 2008}}
5. ^Sheldon B. Markofsky "Nitro Compounds, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.
6. ^¹²³⁴⁵{{cite web|title=Executive Summary - Evaluation of Chloropicrin As A Toxic Air Contaminant|url=http://www.cdpr.ca.gov/docs/emon/pubs/tac/exec_sum_0210.pdf|publisher=Department of Pesticide Regulation - California Environmental Protection Agency|accessdate=20 September 2013|page=iv|format=PDF|date=February 2010}}
7. ^{{cite book |last=Ayres |first=Leonard P. |authorlink = |title =The War with Germany |publisher =United States Government Printing Office |volume = |edition =Second |date =1919 |location =Washington, DC |page =80 |isbn =}}
8. ^¹²³{{cite web|title=Chloropicrin - Background|url=http://www.chloropicrinfacts.org/background.html|accessdate=20 September 2013}}
9. ^¹http://www.workcover.nsw.gov.au/Documents/Publications/AlertsGuidesHazards/DangerousGoodsExplosivesFireworksPyrotechnics/chloropicrin_fact_sheet_1371.pdf {{webarchive |url=https://web.archive.org/web/20090520095913/http://www.workcover.nsw.gov.au/Documents/Publications/AlertsGuidesHazards/DangerousGoodsExplosivesFireworksPyrotechnics/chloropicrin_fact_sheet_1371.pdf |date=May 20, 2009 }}
10. ^{{cite book| author = Amos Alfred Fries|author2=Clarence Jay West| title = Chemical warfare| url = https://books.google.com/books?id=cTA6AAAAMAAJ&pg=PA144| year = 1921| publisher = McGraw-Hill book company, inc.| isbn = | page = 144 }}
11. ^http://termitetenting.com/
12. ^¹{{cite web|title=Chloropicrin Mitigation Proposal|url=http://www.cdpr.ca.gov/docs/whs/pdf/dpr_chloropicrin_mitigation_proposal_and_app_1-3.pdf|publisher=Department of Pesticide Regulation - California Environmental Protection Agency|accessdate=20 September 2013|page=1|format=PDF|date=15 May 2013}}
13. ^{{cite web|title = NIOSH Pocket Guide to Chemical Hazards|url=https://www.cdc.gov/niosh/npg/npgd0132.html|publisher=Centers for Disease Control and Prevention|accessdate=7 November 2013}}
14. ^{{cite web|title=Amended Reregistration Eligibility Decision (RED) for Chloropicrin|url=http://www.epa.gov/oppsrrd1/REDs/chloropicrin-red-amended.pdf|publisher=United States Environmental Protection Agency|accessdate=20 September 2013|format=PDF|date=May 2009}}
15. ^¹{{cite web|title=Chloropicrin Mitigation Proposal|url=http://www.cdpr.ca.gov/docs/whs/pdf/dpr_chloropicrin_mitigation_proposal_and_app_1-3.pdf|publisher=Department of Pesticide Regulation - California Environmental Protection Agency|accessdate=20 September 2013|page=2|format=PDF|date=15 May 2013}}
16. ^¹{{cite web|title=Environmental Protection Agency (EPA) Re-Registers Chloropicrin As Safe For Use Nationwide|url=http://www.chloropicrinfacts.org/safety.html|accessdate=22 October 2013}}
17. ^{{cite web|title=Chloropicrin Mitigation Proposal|url=http://www.cdpr.ca.gov/docs/whs/pdf/dpr_chloropicrin_mitigation_proposal_and_app_1-3.pdf|publisher=Department of Pesticide Regulation - California Environmental Protection Agency|accessdate=20 September 2013|page=2|format=PDF|date=15 May 2013|quote=The Amended RED incorporated final new safety measures to increase protections for agricultural workers and bystanders. These measures establish a baseline for safe use of the soil fumigants throughout the United States, reducing fumigant exposures and significantly improving safety.}}
18. ^{{cite web|title=Chloropicrin - Frequently Asked Questions|url=http://www.chloropicrinfacts.org/faq.html|accessdate=21 October 2013}}
19. ^{{cite web|title=Control Measures for Chloropicrin|url=http://www.cdpr.ca.gov/docs/whs/pdf/control_measures_chloropicrin_summary.pdf|publisher=California Department of Pesticide Regulation|accessdate=January 15, 2015|date=January 6, 2015|quote=added controls for chloropicrin when it is used as a soil fumigant. The controls are intended to reduce risk from acute (short-term) exposures that might occur near fields fumigated with products containing chloropicrin.}}
20. ^{{cite web|title=Chloropicrin Mitigation Proposal|url=http://www.cdpr.ca.gov/docs/whs/pdf/dpr_chloropicrin_mitigation_proposal_and_app_1-3.pdf|publisher=Department of Pesticide Regulation - California Environmental Protection Agency|accessdate=20 September 2013|page=2|format=PDF|date=15 May 2013|quote=The new measures appearing on soil fumigant Phase 2 labels include buffer zones and posting, emergency preparedness and response measures, training for certified applicators supervising applications, Fumigant Management Plans, and notice to State Lead Agencies who wish to be informed of applications in their states.}}
21. ^[https://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750034.html Chloropicrin (PS): Lung Damaging Agent]. National Institute for Occupational Safety and Health. Emergency Response Safety and Health Database, August 22, 2008. Retrieved December 23, 2008.
22. ^{{cite book|url=https://books.google.com/googlebooks/library/index.html|title=Google Books Library Project – An enhanced card catalog of the world's books|publisher=Google|accessdate=26 January 2015}}