About CSIR-NEERI

CSIR-NEERI is endorsed as Stockholm Convention Regional Centre (SCRC) on Persistent Organic Pollutants (POPs) for Asia Region at COP-5 meeting held during 25-29th April 2011 at Geneva. SCRC is serving different parties/countries in Pentachlorobenzene the Asia region to help them in their capacity building and transfer of technologies related to POPs and new POPs. Besides India, CSIR-NEERI is serving ten (PeCB) countries of Asia region viz. Bangladesh, Maldives, Mongolia, Myanmar, Nepal, Philippines Thailand, Sri Lanka, UAE and Vietnam. The goals of the SCRC is to provide technical assistance for building capacities of the parties of the Asia region in relation to monitoring and assessment of POPs in the environment, transfer of technologies, raise awareness and promote identification and environmentally sound management(ESM) of POPs and POPs contaminated sites in the region. The Centre is also assisting the parties of Asia region in fulfilling their obligations of the Stockholm Convention.

Contact us: Director CSIR-National Environmental Engineering Research Institute (CSIR-NEERI) CSIR-National Environmental Engineering Research Institute (Stockholm Convention Regional Centre on POPs for Asia Region) (Stockholm Convention Regional Centre on POPs for Asia Region), Nehru Marg, Nagpur, India-440020 Nagpur, India-440020. Tel: +91-712-2249885-89 (Ext. +332) Fax: +91-712-2249900 Email: [email protected]; [email protected] 1. What is PeCB? 2. What are the characteristics of PeCB? • Pentachlorobenzene (PeCB) are a group of Chlorobenzenes that are characterized by the presence of a benzene ring in IUPAC Name :1,2,3,4,5-pentachlorobenzene which the hydrogen atoms are replaced by five chlorine Molecular formula : C6HCl5 atoms. CAS Number : 608-93-5 • Man-made substance used to make other chemicals such as Colour : White crystalline solid pentachloronitrobenzene (quintozene), a fungicide. Odour : Pleasant aroma • Earlier, PeCB was one component of a Chlorobenzenes Molecular Weight : 250 g/mol mixture used to reduce the viscosity of PCB products Boiling point : 277 °C employed for heat transfer (Environment Canada, 1993). Melting point : 86 °C • PeCBs were also used in a Chlorobenzenes mixture with Water Solubility : 0.81 to 1.34 mg/L at 22-25 °C PCBs in electrical equipment (Environment Canada, 2005). Density : 1.834 g/cm3 at 25 °C Vapor pressure : 2.2 Pa at 25°C Henry´s law constant : 7.03e-04 atm-m3/mol

Log KOW : 4.8-5.18 Log KOA : 6.49

Fig. Structure of PeCB

Source: PubChem 3. What are the applications of PeCBs? 4. Why Pentachlorobenzene a chemical of concern ? • Fungicide  Persistence for longer time in environment, moderately toxic • Dyestuff carrier to human and very toxic to aquatic organisms. • Flame retardant  Accumulation and higher rate of biomagnification in body • Chemical intermediates, likewise used in the production of Quintozene tissues of living organisms and associated with health- • Lubricant to reduce the viscosity of PCB products employed related threats. for heat.  PeCB has been detected in the breast milk and found to accumulate in human placenta (Shen et al., 2007).  Promotes tissue lesions (carcinogens).  Exhibits toxic effect on human reproduction and promotes histopathological changes.  Animals like in poultry exposed to PeCB suffers from weight loss, decrease in egg production and hatching rates.

PeCBs

Applications ©Alamy.com

Heat transfer Fungicide fluid

Flame Retardant Chemical Intermediate

(Source: https://doi.org/10.1016/j.chemosphere.2009.01.038) 5. What are the sources for release in the Unintentional point sources: environment? . By-product of combustion process (incineration and barrel burning of household waste). Intentional point sources: . Yield of PeCB formed strongly depends on combustion conditions . PeCB as a component in PCB products, in dyestuff carriers, as a and the presence of catalytic materials. In uncontrolled conditions, fungicide and a flame retardant and as a chemical intermediate e.g. solid waste incineration like barrel burning, emits far larger production of Quintozene. amounts of chlorobenzenes than controlled incineration (UNECE 2007). . Other sources includes waste streams of paper and pulp mills, iron Air Emission and steel industries and petroleum refineries; impurities in products such as solvents and pesticides. Possible routes of exposure to humans

Industry

Agriculture Contaminated food Contaminated indoor air and dust Landfill

Ground water Drinking water Skin Contact © CSIR-NEERI 6. Evidences in support of prevalence of PeCBs 7. Alternatives of PeCBs? in the environment

 There are no longer any large scale uses of  As there is no current commercial demand for PeCB, no pentachlorobenzene (PeCB). Emissions of PeCB to the alternatives have been identified or developed. PeCB was environment were estimated to be about 121 t/y and the developed for the production of quintozene, Now a days largest sources appeared to be combustion of solid wastes, an alternative process such as chlorination of 32 t/y, biomass burning, 45 t/y with degradation of an nitrobenzene is available for its production. (UNEP- agricultural fungicide, quintozene, contributing 26 t/y POPS-POPRC.4-15-Add.2). (Bailey et al, 2009).  Exposure of rats to 1080mg/kg of PeCB resulted in death of 50% of treated rats (lethal dose/LD50). LD50 for mice exposed to PeCB is 1175 mg/kg (IPCS). US EPA Regional Screening Levels for PeCB

Resident Soil (mg/kg) 6.3E+00 Industrial Soil (mg/kg) 9.3E+01 Tapwater (ug/L) 3.2E-01 Risk-based SSL (mg/kg) 2.4E-03

Source: https://pubchem.ncbi.nlm.nih.gov/compound/11855#section=US-EPA-Regional-Screening-Levels-for- Chemical-Contaminants&fullscreen=true 8. What is the Indian Scenario of PeCBs? 9. Stockholm Convention • Although the intentional production of PeCBs has been • Stockholm Convention on POPs is a global treaty adopted on 22 May 2001 in Sweden and entered into force in 2004, with the prohibited under Stockholm Convention, it is believed to aim to protect human health and environment from chemicals come primarily from unintentional production sources. India that remain intact in the environment for more extended period, is one among the nations which ratified the Stockholm become widely distributed geographically, accumulates in fatty convention and took various important steps for tissues of humans and wildlife and have harmful effects on Environmentally Sound Management of POPs. human health or on the environment. • India ratified and became a member of this Convention on 13 • The Government of India notified the Regulation of January 2006. India is one among the nations which ratified Persistent Organic Pollutants Rule, 2018 (MoEF&CC, the Stockholm Convention and took various important steps in March, 2018), for regulating the manufacture, trade, use, the progress of the prohibition of POPs. import and export of seven chemicals that may be hazardous (http://pib.nic.in/newsite/PrintRelease.aspx?relid=161203) to human and environment. PeCBs is also one of the listed • The Government of India, with financial and technical support chemicals under this rule. from the Global Environment Facility (GEF), initiated the NIP development process which involved the ground-level • Currently, there is no production or stockpiles information assessment of situation of POPs through inventorization, available about Pentachlorobenzene. samples collection, analysis and interpretations (Government of India, 2011). References: - Notes:- . chm.pops.int/ . PubChem, National Center for Biotechnology Information. PubChem Database. Pentachlorobenzene, CID=11855, https://pubchem.ncbi.nlm.nih.gov/compound/Pentachlorobenzene . Environment Canada, 1993. Priority Substances List Assessment Report Pentachlorobenzene . Environment Canada, 2005. Pentachlorobenzene (QCB) and tetrachlorobenzenes (TeCBs) proposed risk management strategy . www.marbef.org/wiki/pentachlorobenzene . www.popstoolkit.com . https://archive.epa.gov/epawaste/hazard/wastemin/web/pdf/pentchlb.pdf. . http://www.bvsde.paho.org/bvsacg/e/cd- cagua/guias/b.parametos/4.BasTox/IPCS/042.chlorobenezenes.pdf . UNECE 2007, https://www.unece.org/fileadmin/DAM/env/lrtap/TaskForce/popsxg/2007/6th meeting/Exploration%20of%20management%20options%20for%20PeCB%20 Final.doc.pdf . Bailey RE, van Wijk D, Thomas PC, 2009. Sources and prevalence of pentachlorobenzene in the environment, Chemosphere.;75(5):555-64.

Disclamation :- The above mentioned data was taken from authentic sources and it is cited well wherever needed. CSIR-NEERI is not taking any responsibility of data cited in this document. The data pertaining to Indian climatic condition is still very limited. The main objective behind compiling information on this particular chemical is for public awareness only.