24478-73-7

Usage

Family

Polychlorinated dibenzofurans (PCDFs)

Formation

Byproduct of industrial processes (e.g., waste incineration) and contaminant in some herbicides

Environmental Persistence

Extremely persistent in the environment

Bioaccumulation

Can bioaccumulate in organisms

Health Risks

Poses significant risk to human and environmental health

Health Effects

Linked to cancer, reproductive disorders, and damage to the immune and nervous systems

Regulatory Measures

Restrictions on production and use, and remediation of contaminated areas

Upstream product

• 33483-06-6 1-hydroxydibenzofuran 
• 87-86-5 Pentachlorophenol 
• 95-57-8 2-monochlorophenol 
• 95-95-4 2,4,5-trichlorophenol 
• 120-83-2 2,4-dichlorophenol 
• 58-90-2 2,3,4,6-tetrachlorophenol 
• 108-95-2 phenol 
• 73575-56-1 2,2',3,5,6-pentachlorobiphenyl 
• 84761-87-5 2,4-Dichloro-dibenzofuran-1-ol 
• 33284-54-7 2,3,5,6-tetrachlorobiphenyl 

Downstream Products

• 71998-73-7 1,2,4,6-tetrachlorodibenzofuran 
• 64126-87-0 1,2,4,8-tetrachlorodibenzofuran 
• 83704-24-9 1,2,4,9-tetrachlorodibenzofuran 
• 83719-40-8 1,2,4,7-Tetrachlorodibenzofuran 

Relevant academic research and scientific papers

Prediction of polychlorinated dibenzofuran congener distribution from gas-phase phenol condensation pathways

A model for predicting the distribution of dibenzofuran and polychlorinated dibenzofuran (PCDF) congeners from a distribution of phenols was developed. The model is based on a simplified chemical mechanism. Relative rate constants and reaction order with respect to phenol precursors were derived from experimental results using single phenols and equal molar mixtures of up to four phenols. For validation, experiments were performed at three temperatures using a distribution of phenol and 19 chlorinated phenols as measured in municipal waste incinerator exhaust gas. Comparison of experimental measurements and model predictions for PCDF isomer distributions and homologue pattern shows agreement within measurement uncertainty. The R-squared correlation coefficient exceeds 0.9 for all PCDF isomer distributions and the distribution of PCDF homologues. These results demonstrate that the distribution of dibenzofuran and the 135 PCDF congeners from gas-phase condensation of phenol and chlorinated phenols can be predicted from measurement of the distribution of phenol and the 19 chlorinated phenol congeners.

Identification of surrogate compounds for the emission of PCDD/F (I-TEQ value) and evaluation of their on-line realtime detectability in flue gases of waste incineration plants by REMPI-TOFMS mass spectrometry

Correlations between products of incomplete combustion (PIC), e.g., chloroaromatic compounds, can be used to characterise the emissions from combustion processes, like municipal or hazardous waste incineration. A possible application of such relationships may be the on-line real-time monitoring of a characteristic surrogate, e.g., with Resonance-Enhanced Multiphoton Ionization-Time-of-Flight Mass Spectrometry (REMPI-TOFMS). In this paper, we report the relationships of homologues and individual congeners of chlorinated benzenes (PCBz), dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and phenols (PCPh) to the International Toxicity Equivalent (I-TEQ) of the PCDD/F (I-TEQ value) in the flue gas and stack gas of a 22 MW hazardous waste incinerator (HWI). As the REMPI detection sensitivity is decreasing with the increase of the degree of chlorination, this study focuses on the lower chlorinated species of the compounds mentioned above. Lower chlorinated species, e.g., chlorobenzene (MCBz), 1,4-dichlorobenzene, 2,4,6-trichlorodibenzofuran or 2,4-dichlorophenol, were identified as I-TEQ surrogates in the flue gas. In contrast to the higher chlorinated phenols, the lower chlorinated phenols (degree of chlorination 4) were not reliable as surrogates in the stack gas. The identified surrogates are evaluated in terms of their detectability by REMPI-TOFMS laser mass spectrometry. The outcome is that MCBz is the best suited surrogate for (indirect) on-line measuring of the I-TEQ value in the flue gas by REMPI-TOFMS. The correlation coefficient r of the MCBz concentration to the I-TEQ in the flue gas was 0.85.

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.

Synthesis of the 38 Tetrachlorodibenzofuran Isomers and Identification by Capillary Column Gas Chromatography/Mass Spectrometry

The 38 positional isomers of tetrachlorodibenzofuran have been synthesized by pyrolysis of specific polychlorinated biphenyl congeners, ultraviolet photolysis of pentachlorodibenzofurans, and chlorination of trichlorodibenzofurans by aromatic substitution.The specificity of these reactions in combinatiuon with capillary column gas chromatography with mass spectrometric detection has allowed each of these isomers to be identified based on their relative elution order.

SELECTIVE PREPARATION. 39. PREPARATION OF SOME CHLORODIBENZOFURANS FROM 1-HYDROXY- AND 2-HYDROXYDIBENZOFURAN

Some chlorodibenzofurans such as 1-chloro, 2-chloro-, 1,2,4-trichloro- and 1,2,3-trichlorodibenzofurans were prepared from 1-hydroxy- and 2-hydroxydibenzofuran.