Characterization of ecological risks from environmental releases of decamethylcyclopentasiloxane (D5)

Decamethylcyclopentasiloxane (D5) is used in personal care products and industrial applications. The authors summarize the risks to the environment from D5 based on multiple lines of evidence and conclude that it presents negligible risk. Laboratory and field studies show that D5 is not toxic to aquatic organisms or benthic invertebrates up to its solubility limit in water or porewater or its sorptive capacity in sediment. Comparison of lipid-normalized internal concentrations with measured concentrations in benthos indicates that field-collected organisms do not achieve toxic levels of D5 in their tissues, suggesting negligible risk. Exposure to D5 resulted in a slight reduction of root biomass in barley at test concentrations 2 orders of magnitude greater than measured D5 levels in biosolids-amended soils and more than twice as high as the maximum calculated sorptive capacity of the soil. No effects were observed in soil invertebrates exposed to similar concentrations, indicating that D5 poses a de minimis risk to the terrestrial environment. High rates of metabolism and elimination of D5 compared with uptake rates from food results in biodilution in the food web rather than biomagnification, culminating in de minimis risk to higher trophic level organisms via the food chain. A fugacity approach substantiates all conclusions that were made on a concentration basis.

[1]  D. Mackay,et al.  Decamethylcyclopentasiloxane (D5) environmental sources, fate, transport, and routes of exposure , 2015, Environmental toxicology and chemistry.

[2]  Daryl J. McGoldrick,et al.  Concentrations and trophic magnification of cyclic siloxanes in aquatic biota from the Western Basin of Lake Erie, Canada. , 2014, Environmental pollution.

[3]  P. Howard,et al.  Identifying new persistent and bioaccumulative organics among chemicals in commerce. , 2010, Environmental science & technology.

[4]  Donald Mackay,et al.  The Evolution and Future of Environmental Fugacity Models , 2009 .

[5]  J. Parrott,et al.  Fathead minnow (Pimephales promelas) embryo to adult exposure to decamethylcyclopentasiloxane (D5). , 2013, Chemosphere.

[6]  P. Howard,et al.  Are there other persistent organic pollutants? A challenge for environmental chemists. , 2006, Environmental science & technology.

[7]  Shihe Xu,et al.  Method for simultaneous determination of partition coefficients for cyclic volatile methylsiloxanes and dimethylsilanediol. , 2012, Analytical chemistry.

[8]  Mehran Alaee,et al.  Concentrations of cyclic volatile methylsiloxanes in biosolid amended soil, influent, effluent, receiving water, and sediment of wastewater treatment plants in Canada. , 2013, Chemosphere.

[9]  A. Cousins,et al.  Results from the Swedish National Screening Programme 2004. : Subreport 2: Octachlorostyrene, Monochlorstyrenes and β-Bromostyrene , 2005 .

[10]  M. Whelan,et al.  Evaluating the fate and behaviour of cyclic volatile methyl siloxanes in two contrasting North American lakes using a multi-media model. , 2013, Chemosphere.

[11]  Mehran Alaee,et al.  Review of recent advances in research on the toxicity, detection, occurrence and fate of cyclic volatile methyl siloxanes in the environment. , 2013, Chemosphere.

[12]  Don Mackay,et al.  An updated state of the science EQC model for evaluating chemical fate in the environment: application to D5 (decamethylcyclopentasiloxane). , 2012, Chemosphere.

[13]  Frank Wania,et al.  Chemical fate, latitudinal distribution and long-range transport of cyclic volatile methylsiloxanes in the global environment: a modeling assessment. , 2013, Chemosphere.

[14]  D. Mackay,et al.  Uncertainty analysis using a fugacity-based multimedia mass-balance model: application of the updated EQC model to decamethylcyclopentasiloxane (D5). , 2013, Chemosphere.

[15]  Eirik Fjeld,et al.  Consistency in trophic magnification factors of cyclic methyl siloxanes in pelagic freshwater food webs leading to brown trout. , 2013, Environmental science & technology.

[16]  W. Norwood,et al.  Decamethylcyclopentasiloxane (D5) spiked sediment: bioaccumulation and toxicity to the benthic invertebrate Hyalella azteca. , 2013, Chemosphere.

[17]  M. Whelan,et al.  Dynamic modelling of aquatic exposure and pelagic food chain transfer of cyclic volatile methyl siloxanes in the Inner Oslofjord. , 2013, Chemosphere.

[18]  Bruce K. Hope,et al.  A Strategy for Using Weight-of-Evidence Methods in Ecological Risk Assessments , 2014 .

[19]  Natasha L. Hoover,et al.  Distribution of phthalate esters in a marine aquatic food web: comparison to polychlorinated biphenyls. , 2004, Environmental science & technology.

[20]  T. Springer,et al.  Bioaccumulation of decamethylpentacyclosiloxane (D5): A review , 2015, Environmental toxicology and chemistry.

[21]  Don Mackay,et al.  Fugacity and activity analysis of the bioaccumulation and environmental risks of decamethylcyclopentasiloxane (D5) , 2015, Environmental toxicology and chemistry.

[22]  M. McLachlan,et al.  Food web accumulation of cyclic siloxanes in Lake Mjøsa, Norway. , 2012, Environmental science & technology.

[23]  G. Suter,et al.  Species Sensitivity Distributions in Ecotoxicology , 2001 .

[24]  P. Paquin,et al.  Tissue‐based risk assessment of cyclic volatile methyl siloxanes , 2012, Environmental toxicology and chemistry.

[25]  J. Tadeo,et al.  Determination of cyclic and linear siloxanes in soil samples by ultrasonic-assisted extraction and gas chromatography-mass spectrometry. , 2010, Journal of chromatography. A.

[26]  J. Hofman,et al.  Comparison and Characterization of OECD Artificial Soils , 2009 .

[27]  S. Charles,et al.  What to do with NOECS/NOELS—prohibition or innovation? , 2012, Integrated environmental assessment and management.

[28]  K. Woodburn,et al.  Determination of the dietary biomagnification of octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane with the rainbow trout (Oncorhynchus mykiss). , 2013, Chemosphere.

[29]  C. E. Cowan,et al.  Technical basis for establishing sediment quality criteria for nonionic organic chemicals using equilibrium partitioning , 1991 .

[30]  Salvador Trinxet,et al.  Canadian Environmental Protection Act, 1999 , 2015 .

[31]  Jessica Velicogna,et al.  Ecotoxicity of siloxane D5 in soil. , 2012, Chemosphere.

[32]  Kurunthachalam Kannan,et al.  Survey of Organosilicone Compounds, Including Cyclic and Linear Siloxanes, in Personal-Care and Household Products , 2008, Archives of environmental contamination and toxicology.