Health & Environmental Research Online (HERO)


tert-Amyl ethyl ether (TAEE)


64 References Were Found:

Data/Software
Data/ Software

ChemIDplus - a TOXNET database

Author: ChemIDplus (2018) National Institutes of Health, U.S. Library of Medicine. HERO ID: 4235826


Archival Material
Archival Material

Online catalog for the Environmental Health Criteria (EHC) monographs

Author: WHO (2016) Available online at http://www.who.int/ipcs/publications/ehc/en/. HERO ID: 783977


Data/Software
Data/ Software

ChemIDplus - a TOXNET database

Author: NLM (2016) Bethesda, MD: National Institutes of Health, U.S. Library of Medicine. HERO ID: 2991424


Data/Software
Data/ Software

OEHHA toxicity criteria database

Author: CalEPA (2016) Sacramento, CA: Office of Environmental Health Hazard Assessment. [Database] HERO ID: 783987


Technical Report
Technical Report

Integrated Risk Information System Program

Author: U.S. EPA (2015) Washington, DC: U.S. Environmental Protection Agency, IRIS. HERO ID: 192196

[Less] The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) Program provides . . . [More] The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) Program provides health effects information on chemicals to which the public may be exposed, providing a critical part of the scientific foundation for EPA's decisions to protect public health. EPA has made several changes to this important Program over the past few years, streamlining the assessment development process, improving transparency, and creating efficiencies within the Program. In April 2011, the National Research Council (NRC) made several recommendations to EPA for improving the development of IRIS assessments. The N RC's recommendations were focused on the development of draft assessments, and the NRC was clear that their intent was not to delay assessments. EPA has made progress in implementing these recommendations. Consistent with the advice of the NRC, EPA is implementing these recommendations using a phased approach and is making the most extensive changes to documents that are in the earlier steps of the assessment development process. For assessments that are in the later stages of development, including assessments that have been posted on the IRIS database since the release of the NRC report, EPA is implementing the recommendations as feasible without taking the assessments backwards to earlier steps of the process. Phase 1 of implementing the NRC recommendations has focused on editing and streamlining documents and using more tables, figures, and appendices. EPA is now in Phase 2 of implementing the NRC recommendations and will soon publicly release two draft IRIS assessments that represent a major advancement in implementing the NRC recommendations. EPA is using a new document structure for these draft assessments, including an Executive Summary presenting major conclusions, a Preamble describing methods used to develop the assessment, distinct sections on Hazard Identification and Dose-Response Analysis, and more tables and figures to clearly present data. Additionally as part of Phase 2, EPA is addressing all of the short-term recommendations provided by the NRC. As part of this effort, EPA will make several changes to IRIS assessments. Highlights include: evaluating and describing the strengths and weaknesses of critical studies in a more uniform way; including toxicity values for multiple effects associated with the chemical, if applicable and where the data allow; routinely considering the use of multiple data sets of combined multiple responses in deriving toxicity values, where appropriate; and evaluating existing guidelines to establish clearer criteria for study selection. Phase 3 of implementation will incorporate the longer-term scientific recommendations made by the NRC. The U.S. Congress has directed EPA to issue a progress report to the House and Senate Committees on Appropriations and relevant Congressional authorizing committees to describe EPA's implementation of the NRC recommendations. This report provides Congress, stakeholders, and the public with an update on the IRIS Program and EPA's progress toward implementing the NRC recommendations and improving the Program.

Technical Report
Technical Report

IARC Monographs on the evaluation of carcinogenic risk to humans

Author: IARC (2015) Geneva, Switzerland: International Agency for Research on Cancer, WHO. HERO ID: 783869


The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Bacterial degradation of tert-amyl alcohol proceeds via hemiterpene 2-methyl-3-buten-2-ol by employing the tertiary alcohol desaturase function of the Rieske nonheme mononuclear iron oxygenase MdpJ

Authors: Schuster, J; Schäfer, F; Hübler, N; Brandt, A; Rosell, M; Härtig, C; Harms, H; Müller, RH; Rohwerder, T (2012) Journal of Bacteriology 194:972-981. HERO ID: 1070868

[Less] Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, . . . [More] Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed.

Technical Report
Technical Report

Benchmark dose technical guidance

Author: U.S. EPA (2012) (EPA/100/R-12/001). Washington, DC: U.S. Environmental Protection Agency, Risk Assessment Forum. HERO ID: 1239433


The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Biofilm formation and microbial activity in a biofilter system in the presence of MTBE, ETBE and TAME

Authors: Purswani, J; Juárez, B; Rodelas, B; Gónzalez-López, J; Pozo, C (2011) Chemosphere 85:616-624. HERO ID: 1070886

[Less] Emerging water contaminants derived from unleaded gasoline such as methyl tert-butyl ether (MTBE), ethyl . . . [More] Emerging water contaminants derived from unleaded gasoline such as methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME), are in need of effective bioremediation technologies for restoring water resources. In order to design the conditions of a future groundwater bioremediating biofilter, this work assesses the potential use of Acinetobacter calcoaceticus M10, Rhodococcus ruber E10 and Gordonia amicalis T3 for the removal of MTBE, ETBE and TAME in consortia or as individual strains. Biofilm formation on an inert polyethylene support material was assessed with scanning electron microscopy, and consortia were also analysed with fluorescent in situ hybridisation to examine the relation between the strains. A. calcoaceticus M10 was the best coloniser, followed by G. amicalis T3, however, biofilm formation of pair consortia favoured consortium M10-E10 both in formation and activity. However, degradation batch studies determined that neither consortium exhibited higher degradation than individual strain degradation. The physiological state of the three strains was also determined through flow cytometry using propidium iodide and 3'-dihexylocarbocyanine iodide thus gathering information on their viability and activity with the three oxygenates since previous microbial counts revealed slow growth. Strain E10 was observed to have the highest physiological activity in the presence of MTBE, and strain M10 activity with TAME was only maintained for 24 h, thus we believe that biotransformation of MTBE occurs within the active periods established by the cytometry analyses. Viable cell counts and oxygenate removal were determined in the presence of the metabolites tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA), resulting in TBA biotransformation by M10 and E10, and TAA by M10. Our results show that A. calcoaceticus M10 and the consortium M10-E10 could be adequate inocula in MTBE and TAME bioremediating technologies.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Formation of alkenes via degradation of tert-alkyl ethers and alcohols by Aquincola tertiaricarbonis L108 and Methylibium spp

Authors: Schäfer, F; Muzica, L; Schuster, J; Treuter, N; Rosell, M; Harms, H; Müller, RH; Rohwerder, T (2011) Applied and Environmental Microbiology 77:5981-5987. HERO ID: 1070887

[Less] Bacterial degradation pathways of fuel oxygenates such as methyl tert-butyl and tert-amyl methyl ether . . . [More] Bacterial degradation pathways of fuel oxygenates such as methyl tert-butyl and tert-amyl methyl ether (MTBE and TAME, respectively) have already been studied in some detail. However, many of the involved enzymes are still unknown, and possible side reactions have not yet been considered. In Aquincola tertiaricarbonis L108, Methylibium petroleiphilum PM1, and Methylibium sp. strain R8, we have now detected volatile hydrocarbons as by-products of the degradation of the tert-alkyl ether metabolites tert-butyl and tert-amyl alcohol (TBA and TAA, respectively). The alkene isobutene was formed only during TBA catabolism, while the beta and gamma isomers of isoamylene were produced only during TAA conversion. Both tert-alkyl alcohol degradation and alkene production were strictly oxygen dependent. However, the relative contribution of the dehydration reaction to total alcohol conversion increased with decreasing oxygen concentrations. In resting-cell experiments where the headspace oxygen content was adjusted to less than 2%, more than 50% of the TAA was converted to isoamylene. Isobutene formation from TBA was about 20-fold lower, reaching up to 4% alcohol turnover at low oxygen concentrations. It is likely that the putative tert-alkyl alcohol monooxygenase MdpJ, belonging to the Rieske nonheme mononuclear iron enzymes and found in all three strains tested, or an associated enzymatic step catalyzed the unusual elimination reaction. This was also supported by the detection of mdpJK genes in MTBE-degrading and isobutene-emitting enrichment cultures obtained from two treatment ponds operating at Leuna, Germany. The possible use of alkene formation as an easy-to-measure indicator of aerobic fuel oxygenate biodegradation in contaminated aquifers is discussed.