40321-76-4

Basic information

• Product Name: 1,2,3,7,8-PENTACHLORODIBENZO-P-DIOXIN
• Synonyms: 1,2,3,7,8-pentachloro-dibenzo-p-dioxi;1,2,3,7,8-Pentachlorooxanthrene;Dibenzo-p-dioxin, 1,2,3,7,8-pentachloro-;1,2,3,7,8-PENTACHLORODIBENZODIOXIN;1,2,3,7,8-PECDD;1,2,3,7,8-PENTACHLORODIBENZO-PARA-DIOXIN;1,2,3,7,8-PCDD;1,2,3,7,8-PNCDD
• CAS NO: 40321-76-4
• Molecular Formula: C₁₂H₃Cl₅O₂
• Molecular Weight: 356.41602
• Product Categories: Aromatics;Heterocycles
• Mol File: 40321-76-4.mol

Chemical Properties

• Melting Point: 206°C (estimate)
• Boiling Point: 442.63°C (rough estimate)
• Flash Point: 174°C
• Appearance: /
• Density: 1.7800 (estimate)
• Vapor Pressure: 8.14E-08mmHg at 25°C
• Refractive Index: 1.6610 (estimate)
• CAS DataBase Reference: 1,2,3,7,8-PENTACHLORODIBENZO-P-DIOXIN(CAS DataBase Reference)
• NIST Chemistry Reference: 1,2,3,7,8-PENTACHLORODIBENZO-P-DIOXIN(40321-76-4)
• EPA Substance Registry System: 1,2,3,7,8-PENTACHLORODIBENZO-P-DIOXIN(40321-76-4)

Safety Data

• RIDADR: 2811
• HazardClass: 6.1(a)
• PackingGroup: I
• Hazardous Substances Data: 40321-76-4(Hazardous Substances Data)

Usage

Safety Profile

Poison by ingestion. Questionable carcinogen. When heated to decomposition it emits toxic fumes of Clí.

InChI:InChI=1/C12H3Cl5O2/c13-4-1-7-8(2-5(4)14)19-12-9(18-7)3-6(15)10(16)11(12)17/h1-3H

Upstream product

• 262-12-4 dioxin 
• 39227-28-6 1,2,3,4,7,8-hexachlorodibenzodioxin 
• 58-89-9 LINDANE 
• 120-36-5 2-(2,4-dichlorophenoxy)propionic acid 
• 95-95-4 2,4,5-trichlorophenol 

Relevant articles and documents

PCDD/DF formations by the heterogeneous thermal reactions of phenols and their TiO2 photocatalytic degradation by batch-recycle system

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) formation by the thermal reactions of phenols with CuCl2 under oxygen flux were carried out in relation to their formation mechanisms: To evaluate the effect of photocatalytic degra

Effects of oxygen on formation of PCB and PCDD/F on extracted fly ash in the presence of carbon and cupric salt

The effect of oxygen-nitrogen atmosphere (N2 + 10%O2, N2 + 1%O2 and 99.999% N2) on the formation of PCB, PCDD and PCDF by the de novo synthetic reactions in the system consisting of extracted fly ash

Formation and emission status of PCDDS/PCDFS in municipal solid waste incinerators in korea

This study was carried out to examine the formation and the emission status of polychlorinated dibenzo-p-dioxins/ polychlorinated dibenzofurans (PCDDs/PCDFs) in the flue gases of commercial-scale municipal solid waste (MSW) incinerators, and thus to provi

Dioxins from thermal and metallurgical processes: Recent studies for the iron and steel industry

In thermal metallurgical processes such as iron ore sintering and metal smelting operations, large flows of off-gases are generated. Mainly due to residue recycling in such processes, chlorine and volatile organics are always present in the feed. As a consequence of de novo formation, the off-gases from such processes typically contain dioxins in the range 0.3-30 ng I-TEQ/Nm3. So far there are only very few studies about the mechanisms of dioxin formation and destruction in these metallurgical processes. In an European Union (EU) research project Minimization of dioxins in thermal industrial processes: mechanisms, monitoring and abatement (MINIDIP) , integrated iron and steel plant has been selected as one of the industrial sectors for further investigation. A large number of particulate samples (feed, belt siftings, electrofilter) were collected from the iron ore sintering installations from various steel plants and analyzed for their organochlorocompound contents. Measurable amounts of PCDD/F, PCBz, PCB were found for all samples. The various parameters influencing their de novo synthesis activity were also evaluated in laboratory experiments, and such activity was found to be moderate for samples from the ore sinter belt, but extremely high for some ESP dusts. Fine dust is active in a wide range of temperatures starting at 200°C and declining above 450°C; the optimal temperature for de novo synthesis was found to be around 350°C; some inhibitors, such as triethanolamine, may reduce de novo activity by 50%, and lowering the O2 concentration in the gas stream leads to a much lower amount of PCDD/F formation. On the basis of their relative mass, typical operating conditions and specific activity of the different samples, the regions in the sintering plant where de novo synthesis may take place were tentatively established.

The effect of oils on PAH, PCDD, PCDF, and PCB emissions from a spark engine fueled with leaded gasoline

The effect of synthetic and mineral oils on the formation of polyaromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in emissions from a spark ignition engine was studied on a Skoda Favorit engine fueled with leaded gasoline. The test cycle simulated urban traffic conditions on a chassis dynamometer, in accordance with the ECC 83.00 test. The data for selected PAHs as well as PCDDs, PCDFs, and PCBs congener profiles are presented. PCDD/Fs emissions for an unused oil and the oil after 10 000-km operation varied from 300 to 2000 fmol/m3, PCBs emissions from 75 to 178 pmol/m3, and PAHs emissions from 150 to 420 μg/m3. The content of PCBs in oils varied from 2 to 920 mg/kg.

Study of evolution of PCDD/F in sewage sludge-amended soils for land restoration purposes

The evolution of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in sewage sludge-amended soils used in the restoration of degraded lands, like quarries, has been studied. Two experiments were performed: one in the lab, under controlled conditions, and another in a quarry. Two different doses of sewage sludge were applied in both experiments (with two types of application in the quarry experiment) and the evolution of the amended soils were compared with that of the respective control soils (without addition of sewage sludge). The samples were analyzed with a previously validated method by HRGC-HRMS after the extraction and the necessary clean-up steps. The results reveal that polluted sewage sludge increases PCDD/F concentration in soils and that these compounds are persistent in the matrix after long periods of time. (C) 2000 Elsevier Science Ltd. The evolution of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in sewage sludge-amended soils used in the restoration of degraded lands, like quarries, has been studied. Two experiments were performed: one in the lab, under controlled conditions, and another in a quarry. Two different doses of sewage sludge were applied in both experiments (with two types of application in the quarry experiment) and the evolution of the amended soils were compared with that of the respective control soils (without addition of sewage sludge). The samples were analyzed with a previously validated method by HRGC-HRMS after the extraction and the necessary clean-up steps. The results reveal that polluted sewage sludge increases PCDD/F concentration in soils and that these compounds are persistent in the matrix after long periods of time. Laboratory and field experiments were conducted in Spain to examine the evolution of PCDDs and PCDFs in sewage-sludge-amended soils. The PCDD/F concentrations were measured in the original sewage sludge and in soil samples over time. Results from the laboratory showed that the PCDD/F concentration in amended soils was related directly to the sewage-sludge dose applied. After 1 yr, however, no evolution of PCDD/Fs was observed in any sample. In the field, high dispersion was observed, which did not allow establishment of a concentration trend over time. (from Eighteenth Symp on Halogenated Environ Organic Pollutants-Dioxin '98, Stockholm, Sweden (Aug 17-21, 98)).

Determination of polychlorinated dibenzo-p-dioxins and dibenzo-furans in solid residues from wood combustion by HRGC/HRMS

PCDD/PCDF were determined in solid samples from wood combustion. The samples included grate ashes, bottom ashes, furnace ashes as well as fly and cyclone ashes. The solid waste samples were classified into bottom and fly ash from native wood and bottom and fly ash from waste wood. For each of the four classes concentration distribution patterns from individual congeners, the sums of PCDD/PCDF and the international toxicity equivalents (I-TEQ) values are given. The I-TEQ levels of fly ash from waste wood burning can be approximately up to two thousand times higher than the values from fly ashes of natural wood. The I-TEQ levels in bottom ashes from waste wood combustion systems are as low as the corresponding ashes from the combustion of native wood. Grate ash samples from waste wood combustion systems with low carbon burnout show high levels of PCDD/PCDF.

Estimation of dioxin emission from fires in chemicals

The formation of the 17 toxic 2,3,7,8-substituted-PCDDs and PCDFs during combustion of selected chemicals were measured by high-resolution GC/MS. The 16 chemicals studied were commonly used chlorinated pesticides, industrial chemicals, and PVC. In a series of experiments carried out in a DIN 53,436 furnace, 2.5 g of these compounds were burned at 500°C and 900°C, respectively. The resultant yields ranged from 740 ng ITEQ/g for pentachlorophenol, to below 0.01 ng ITEQ/g for PVC and dichlobenil. The results show that some chemicals generate PCDD/F in very high - possibly dangerous - amounts during burning, whereas others generate insignificant amounts. The influence of scale were studied for chlorobenzene and 4-chloro- 3-nitro-benzoic acid in additional experiments, carried out in a cone calorimeter burning 20 g substance, and in ISO 9705 room test burning about 50 kg. A good agreement between the results for large and small scale indicated that formation of PCCD/F during a fire may be estimated from laboratory experiments. This suggest laboratory test may be used to screen for chemicals posing a hazard for release of PCDD/F during fires.

Natural formation of chlorinated phenols, dibenzo-p-dioxins, and dibenzofurans in soil of a Douglas fir forest

The natural formation of 4-MCP, 24/25- and 26-DCP, and 245-TrCP was detected in four selected areas of a rural Douglas fir forest where the humic layer was spiked in situ with a solution of Na37Cl and covered by an enclosure, after 1 year of incubation. Chlorinated phenols (CP) can be formed naturally from organic matter and inorganic chloride by either de novo synthesis or chloroperoxidase (CPO)-catalyzed chlorination. The natural CP congeners were found to be present in high concentrations in soil compared to the other congeners, except for 245-TrCP which was present in a relatively low concentration. This study did not reveal which source, natural or anthropogenic, caused the observed concentrations. Some 20 chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/F) were found to be formed naturally in soil of the Douglas fir forest; the formation of three 2,3,7,8-substituted congeners, 2378-TeCDD, 12378-PeCDD, and 123789-HxCDD, deserves special attention. A formation mechanism has been proposed which starts from naturally formed CP congeners and which probably involves peroxidase mediation. Chlorination of CDD/F congeners by the CPO-mediated reaction cannot be ruled out, but seems to be less likely due to the absence of several predicted congeners. The natural formation of 4-MCP, 24/25- and 26-DCP, and 245-TrCP was detected in four selected areas of a rural Douglas fir forest where the humic layer was spiked in situ with a solution of Na37Cl and covered by an enclosure, after 1 year of incubation. Chlorinated phenols (CP) can be formed naturally from organic matter and inorganic chloride by either de novo synthesis or chloroperoxidase (CPO)-catalyzed chlorination. The natural CP congeners were found to be present in high concentrations in soil compared to the other congeners, except for 245-TrCP which was present in a relatively low concentration. This study did not reveal which source, natural or anthropogenic, caused the observed concentrations. Some 20 chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/F) were found to be formed naturally in soil of the Douglas fir forest; the formation of three 2,3,7,8-substituted congeners, 2378-TeCDD, 12378-PeCDD, and 123789-HxCDD, deserves special attention. A formation mechanism has been proposed which starts from naturally formed CP congeners and which probably involves peroxidase mediation. Chlorination of CDD/F congeners by the CPO-mediated reaction cannot be ruled out, but seems to be less likely due to the absence of several predicted congeners.

Isomer distributions of polychlorinated dibenzo-p-dioxins/dibenzofurans formed during de novo synthesis on incinerator fly ash

Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) emitted from municipal waste incinerators appear to have a chlorination pattern that is quite constant across various samples and conditions. This suggested that these patterns may be controlled by thermodynamic properties of the individual PCDD/F congeners, such as the free Gibbs energy of formation (Δg°(f,T)). This would make prediction of the isomer composition of a particular sample (and hence its TEQ value) possible, based on values of ΔG°(f,T). A laboratory scale study was carried out with activated carbon on fly ash as the source of PCDD/F formation. Although it was found that the isomer distributions within homologues were independent of the reaction time (proof of thermodynamic control), other observations (lack of equilibrium/isomerization between isomers and lack of similarity between isomer distributions measured and predicted by ΔG°(f,T)) contradicted the possibility of thermodynamic control. Hence, this study could not confirm that de novo formation of PCDD/F could explain thermodynamically controlled isomer distributions in incinerators. Some recommendations for further work- time-based studies with precursors, isomerization studies with single congeners, and more data on ΔG°(f,T) values of PCDD/F-were made. Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) emitted from municipal waste incinerators appear to have a chlorination pattern that is quite constant across various samples and conditions. This suggested that these patterns may be controlled by thermodynamic properties of the individual PCDD/F congeners, such as the free Gibbs energy of formation (ΔG°f,T). This would make prediction of the isomer composition of a particular sample (and hence its TEQ value) possible, based on values of ΔG°f,T. A laboratory scale study was carried out with activated carbon on fly ash as the source of PCDD/F formation. Although it was found that the isomer distributions within homologues were independent of the reaction time (proof of thermodynamic control), other observations (lack of equilibrium/isomerization between isomers and lack of similarity between isomer distributions measured and predicted by ΔG°f,T) contradicted the possibility of thermodynamic control. Hence, this study could not confirm that de novo formation of PCDD/F could explain thermodynamically controlled isomer distributions in incinerators. Some recommendations for further work - time-based studies with precursors, isomerization studies with single congeners, and more data on ΔG°f,T values of PCDD/F - were made.