Environmental risk assessment for relevant ingredients in adhesives and sealants in commonplace industrial uses.

The Regulation on Registration, Evaluation, Authorisation and Restriction of Chemicals requires that the risks from the exposure to substances be controlled throughout the life cycle. This includes that conditions of safe use are established via risk assessments, documented and communicated to the downstream users of chemicals. This also applies to the environmental risks originating from downstream uses of chemicals, for instance, those from the industrial uses of adhesives and sealants. Upon application, these products form solid matrices with low emissions to the environment during the application. Hence, it is expected that environmental exposure is low, provided that good industrial practice is followed. To explore this, an environmental risk assessment for industrial uses of adhesives and sealants is performed for the environmentally most hazardous ingredients. These include several solvents, organotin catalysts, fillers, reactive resins, a pigment, and a preservative. Specific environmental release categories (SPERCs) developed by the Association of European Adhesives and Sealants Industries (FEICA) are used to derive emission estimates. In combination with multimedia fate modeling, the environmental risk in water, sediment, soil, and a sewage treatment plant is investigated. The assessment results indicate no environmental risk for any of the ingredients. The discussion evaluates the conservative nature of the assumed values of the use rates, the release factors, the fate modeling, and assessment factors. It concludes that their combination results in a sufficient degree of conservatism. In view of the conservative nature of the assessment and given that the worst-case ingredients of adhesives and sealants are sufficiently controlled under the generically defined use conditions, it is concluded that the SPERCs used represent safe conditions for use, irrespective of the ingredient substances of adhesives and sealants. The essential SPERC information elements are identified for the purpose of communicating the conditions of safe use. The consolidation of this information in safety data sheets for adhesives and sealants is discussed. Environ Assess Manag 2022;18:1288-1296. © 2021 FEICA aisbl. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Use of prospective and retrospective risk assessment methods that simplify chemical mixtures associated with treated domestic wastewater discharges.

A framework is presented that is intended to facilitate the evaluation of potential aquatic ecological risks resulting from discharges of down-the-drain chemicals. A scenario is presented using representatives of many of the types of chemicals that are treated domestically. Predicted environmental chemical concentrations are based on reported loading rates and routine removal rates for 3 types of treatment: trickling filter, activated sludge secondary treatment, and activated sludge plus advanced oxidation process as well as instream effluent dilution. In tier I, predicted effluent concentrations were compared with the lowest predicted-no-effect concentration (PNEC) obtained from the literature using safety factors as needed. A cumulative risk characterization ratio (cumRCR) < 1.0 indicates that risk is unlikely and no further action is needed. Otherwise, a tier 2 assessment is used, in which PNECs are based on trophic level. If tier 2 indicates a possible risk, then a retrospective assessment is recommended. In tier 1, the cumRCR was > 1.0 for all 3 treatment types in our scenario, even though no chemical exceeded a hazard quotient of 1.0 in activated sludge or advanced oxidation process. In tier 2, activated sludge yielded a lower cumRCR than trickling filter because of higher removal rates, and the cumRCR in the advanced oxidation process was << 1.0. Based on the maximum cumulative risk ratio (MCR), more than one-third of the predicted risk was accounted for by one chemical, and at least 90% was accounted for by 3 chemicals, indicating that few chemicals influenced the mixture risk in our scenario. We show how a retrospective assessment can test whether certain chemicals hypothesized as potential drivers in the prospective assessment could have, or are having, deleterious effects on aquatic life. Environ Toxicol Chem 2018;37:690-702. © 2017 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

European Union regulators and industry agree on improving specific environmental release categories: Report from the exchange network for exposure scenarios specific environmental release category workshop on May 13, 2016.

Specific environmental release categories (SPERCs) are an instrument for lower-tier environmental emissions assessments. They support chemical safety assessments under the European Union (EU) regulation Registration, Evaluation, Authorisation, and Restriction of Chemicals. SPERCs have been developed by industry and subjected to regulatory review. Within the framework of the Chemical Safety Report/Exposure Scenario Roadmap, the EU Chemicals Agency (ECHA), the EU Member State authorities, and European industry sector associations collaborate to improve the quality of the SPERCs. Following up on the outcome of ECHA's SPERC Best Practice Project, industry, together with ECHA, developed an updated SPERC factsheet template and guidance on how to fill it out. In addition, industry developed 2 sets of SPERC factsheet examples and the corresponding SPERC background documents. These documents were submitted to a multistakeholder review process. The comments from the review were discussed at a workshop in spring 2016. The workshop participants acknowledged the revised factsheet format including the corresponding guidance, the 2 SPERC factsheets, and the 2 SPERC background documents as best practice examples. The package is expected to support further improvement of the quality of the SPERCs. A common understanding was achieved of the need to match the level of detail of the use conditions description with the risk to be controlled (i.e., the emission intensity and hazard profile of the substances) and with the level of conservatism of SPERC release factors. The complete and transparent documentation of the derivation of the release factors and of their conservatism is conceived as crucial for the credibility of the SPERCs, such that they can be trusted by partners in the chemicals supply chain and by regulators. To that end, background documents will include a dedicated section describing the conservatism of SPERCs. The workshop concluded with an outline of the practical way forward for the improvement of SPERC documentation. Integr Environ Assess Manag 2017;13:815-820. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

SPERCS-A tool for environmental emission estimation.

The European Union (EU) chemicals regulation Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) requires a hazardous substance registration to identify the uses of a substance and the corresponding conditions of safe use. This requirement includes a human and an environmental safety assessment. Exposure scenarios are developed and employed for estimating emissions resulting from the uses of hazardous substances. To support the environmental assessments, the REACH guidance documents define 22 environmental release categories (ERCs) with conservative release factors (RFs) to water, air, and soil. Several industry associations target the ERCs to more specific uses and respective emission scenarios to enable more realistic emission estimations. They have developed more than 190 specific ERCs (SPERCs) as standardized descriptions of operational conditions (OCs) and risk management measures (RMMs). SPERCs reflect the current good practice and are documented in factsheets. These factsheets contain the information necessary for environmental emission modeling. Key parameters are the substance use rate, the efficiency of the risk management measures (if applicable), and the RFs. These parameters can be based on literature or measured company data or are justified by qualitative arguments. The majority of SPERCs have been implemented as realistic worst-case emission values in screening-level chemical safety assessment (CSA) tools. Three regulatory reviews in Europe have established requirements for documenting the SPERCs and for justifying the RFs. In addition, each of the reviews included recommendations for improving the SPERCs. The latest review proposed a condensed factsheet that focuses on the essentials for exposure assessment and subsequent communication in safety data sheets. It is complemented with a background document for providing details on the emission scenarios and justifications. In the EU the SPERCs will be further progressed in a consensus process using the multi-stakeholder expert network on exposure scenarios. The SPERCs have the potential to be used in environmental risk assessments within other regulatory frameworks or in other geographical regions. Integr Environ Assess Manag 2016;12:772-781. © 2015 SETAC.

Estimating emissions from adhesives and sealants uses and manufacturing for environmental risk assessments.

Regulation (EC) No 1907/2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) requires that environmental exposure assessments be performed for all uses of dangerous substances that are marketed in the European Union in quantities above 10 tons per year. The quantification of emissions to the environment is a key step in this process. This publication describes the derivation of release factors and gives guidance for estimating use rates for quantifying the emissions from the manufacturing and application of adhesives and sealants. Release factors available for coatings and paints are read across to adhesives or sealants based on similarities between these 2 product groups with regard to chemical composition and to processing during manufacturing and application. The granular emission scenarios in these documents are mapped to the broad emission scenarios for adhesives or sealants. According to the mapping, the worst-case release factors for coatings or paints are identified and assigned to the adhesives or sealants scenarios. The resulting 10 specific environmental release categories (SPERCs) for adhesives and sealants are defined by differentiating between solvent and nonsolvent ingredients and between water-borne and solvent-borne or solvent-free products. These cover the vast majority of the production processes and uses and are more realistic than the 5 relevant emission estimation defaults provided in the REACH guidance. They are accompanied with adhesive or sealant consumption rates in the EU and with guidance for estimating conservative substance use rates at a generic level. The approach of combining conservative SPERC release factors with conservative estimates of substance rates is likely to yield emission estimates that tend to overpredict actual releases. Because this qualifies the approach for use in lower-tier environmental exposure assessment, the Association of the European Adhesive & Sealant Industry (FEICA) SPERCs are available in several exposure assessment tools that are used under REACH. Given the limited regional variation in the manufacturing and use processes of adhesives and sealants, the SPERCs may be applicable for emission estimation not only in the EU but also in other regions.

Specific environmental release categories--A tool for improving chemical safety assessment in the EC--report of a multi-stakeholder workshop.

In April 2011, experts from industry and authorities met for a workshop to discuss experience and future developments regarding the use of specific environmental release categories (SPERCs) in chemicals safety assessment (CSA) under the European Chemicals Regulation Registration, Evaluation and Authorization of Chemicals (REACH). This article provides a summary of the workshop. It briefly explains what a SPERC is, why SPERCs are needed, where the challenges of the concept are, and what improvements are needed to make SPERCs a useful tool for assessments under REACH.

A new concept for the environmental risk assessment of poorly water soluble compounds and its application to consumer products.

Many consumer products contain lipophilic, poorly soluble ingredients representing large-volume substances whose aquatic toxicity cannot be adequately determined with standard methods for a number of reasons. In such cases, a recently developed approach can be used to define an aquatic exposure threshold of no concern (ETNCaq; i.e., a concentration below which no adverse affects on the environment are to be expected). A risk assessment can be performed by comparing the ETNCaq value with the aquatic exposure levels of poorly soluble substances. Accordingly, the aquatic exposure levels of substances with water solubility below the ETNCaq will not exceed the ecotoxicological no-effect concentration; therefore, their risk can be assessed as being negligible. The ETNCaq value relevant for substances with a narcotic mode of action is 1.9 microg/L. To apply the above risk assessment strategy, the solubility in water needs to be known. Most frequently, this parameter is estimated by means of quantitative structure/activity relationships based on the log octanol-water partition coefficient (log Kow). The predictive value of several calculation models for water solubility has been investigated by this method with the use of more recent experimental solubility data for lipophilic compounds. A linear regression model was shown to be the most suitable for providing correct predictions without underestimation of real water solubility. To define a log Kow threshold suitable for reliably predicting a water solubility of less than 1.9 microg/L, a confidence limit was established by statistical comparison of the experimental solubility data with their log Kow. It was found that a threshold of log Kow = 7 generally allows discrimination between substances with solubility greater than and less than 1.9 microg/L. Accordingly, organic substances with a baseline toxicity and log Kow > 7 do not require further testing to prove that they have low environmental risk. In applying this concept, the uncertainty of the prediction of water solubility can be accounted for. If the predicted solubility in water is to be below ETNCaq with a probability of 95%, the corresponding log Kow value is 8.

The effect of pH and ionic strength on the sorption of sulfachloropyridazine, tylosin, and oxytetracycline to soil.

Antimicrobial agents are the most heavily used pharmaceuticals in intensive husbandry. Their usual discharge pathway is application to agricultural land as constituents of animal manure, which is used as fertilizer. Many of these compounds undergo pH-dependent speciation and, therefore, might occur as charged species in the soil environment. Hence, pH and ionic strength of the soil suspension can affect the sorption behavior of these compounds to soil. Consequently, the soil sorption of three antimicrobial agents--sulfachloropyridazine (SCP), tylosin (TYL), and oxytetracycline (OTC)--was investigated. Their respective sorption coefficients in two agricultural soils ranged from 1.5 to 1,800 L/kg. Sorption coefficients were greater under acidic conditions. Addition of an electrolyte to the solution led to decreased sorption of TYL and OTC by a factor of 3 to 20, but it did not influence the sorption of SCP. This behavior was analyzed by accounting for the pH-dependent speciation of TYL and OTC and considering the presence of OTC-calcium complexes. It appears that the decreased sorption of TYL and OTC with increasing ionic strength results from competition of the electrolyte cations with the positively charged TYL species and the positively charged OTC complexes. A model linking sorbate speciation with species-specific sorption coefficients can describe the pH dependence of the apparent sorption coefficients. This modeling approach is proposed for implementation in the assessment of sorption of ionizable compounds.

Estimation of soil sorption coefficients of veterinary pharmaceuticals from soil properties.

Environmental exposure assessment of veterinary pharmaceuticals requires estimating the sorption to soil. Soil sorption coefficients of three common, ionizable, antimicrobial agents (oxytetracycline [OTC], tylosin [TYL], and sulfachloropyridazine [SCP]) were studied in relation to the soil properties of 11 different soils. The soil sorption coefficient at natural pH varied from 950 to 7,200, 10 to 370, and 0.4 to 35 L/kg for OTC, TYL, and SCP, respectively. The variation increased by almost two orders of magnitude for OTC and TYL when pH was artificially adjusted. Separate soil properties (pH, organic carbon content, clay content, cation-exchange capacity, aluminum oxyhydroxide content, and iron oxyhydroxide content) were not able to explain more than half the variation observed in soil sorption coefficients. This reflects the complexity of the sorbent-sorbate interactions. Partial-least-squares (PLS) models, integrating all the soil properties listed above, were able to explain as much as 78% of the variation in sorption coefficients. The PLS model was able to predict the sorption coefficient with an accuracy of a factor of six. Considering the pH-dependent speciation, species-specific PLS models were developed. These models were able to predict species-specific sorption coefficients with an accuracy of a factor of three to four. However, the species-specific sorption models did not improve the estimation of sorption coefficients of species mixtures, because these models were developed with a reduced data set at standardized aqueous concentrations. In conclusion, pragmatic approaches like PLS modeling might be suitable to estimate soil sorption for risk assessment purposes.

Pollution-induced community tolerance of soil microbial communities caused by the antibiotic sulfachloropyridazine.

Little is known about the environmental hazards linked to the treatment of farm animals with antibiotics and subsequent spreading of manure, especially regarding soil microbial communities. In this investigation, pollution-induced community tolerance (PICT) of bacteria from soils artificially spiked with the sulfonamide sulfachloropyridazine (SCP) was investigated. Tolerance of the bacterial communities after 3 weeks' exposure to SCP was determined by analyzing the sensitivity of 31 microbial metabolic processes in microtiter plates. Bacterial suspensions extracted from soils containing higher concentrations of SCP showed an increased tolerance of their metabolic activities to this antibiotic. An increase in tolerance by 10% was found at 7.3 mg/kg dw SCP. The PICT effect could be demonstrated by both a shift in the tolerance of the average of all metabolic activities and a shift of the physiological process sensitivity distributions made up from the single metabolic processes. The PICT effect was accompanied by smaller changes in the community-level physiological profile (CLPP). To conclude, PICT has been shown to be a versatile and illustrative method for the detection of the effects of antibacterial agents on soil microorganisms.

Slow-stirring method for determining the n-octanol/water partition coefficient (Pow) for highly hydrophobic chemicals: performance evaluation in a ring test.

The n-octanol/water partition coefficient (Pow) is one of the most important parameters employed for estimating a chemical's environmental fate and toxicity. The currently adopted test guidelines for its determination do not allow for reliable determination of log Pow greater than 5. The slow-stirring experiment, in contrast, has been demonstrated to provide reliable log Pow data up to log Pow of 8.3. To validate this method and to obtain its approval as an official Organization for Economic Cooperation and Development (Paris, France) test guideline, a ring test was performed to evaluate the accuracy and precision of the slow-stirring experiment for determination of log Pow, particularly for highly hydrophobic compounds. Up to 15 volunteer laboratories tested 1,2,3,4-tetrachlorobenzene, hexachlorobenzene. 2,2',3,3',5,5',6,6'-octachlorobiphenyl, and decachlorobiphenyl (4.5 < log Pow < 8.2). The ring-test results for the respective chemicals were 4.62, 5.50, 7.39, and 8.18. The results deviated by less than 0.1 log Pow units from the reference log Pow. In addition, the relative standard deviations of log Pow were less than 2%. Using the protocol of the ring test, log Pow of p,p'-DDT was determined to be 6.24 +/- 0.05 (mean +/- standard deviation). In combination, these results indicate that the slow-stirring method is precise and accurate and, thus, allows for reliable determination of log Pow of highly hydrophobic chemicals.

Measured pore-water concentrations make equilibrium partitioning work--a data analysis.

There is an increasing body of evidence that the bioaccumulation of sediment-associated hydrophobic organic compounds (HOCs) is strongly influenced by sequestration. At present, it is not known how equilibrium partitioning theory (EqP), the most commonly employed approach for describing sediment bioaccumulation can be applied to sediments with sequestered contaminants. In this paper, we present freely dissolved pore-water concentrations of HOCs. These data were employed to interpret sediment bioaccumulation and sequestration data in order to arrive at a process based evaluation of EqP. The data analysis suggests that sediment bioaccumulation of compounds up to log K(ow) 7.5 in Tubificidae can be described as bioconcentration from pore-water. In addition, the pore-water concentrations of HOCs (4.5 < log K(ow) < 7.5) are established by equilibrium partitioning between the rapidly desorbing HOCs fraction in the sediment and the pore-water. Taken together, these findings indicate that EqP is a conceptually correct representation of sediment bioaccumulation, provided that sequestration is accounted for. This implies that the risk assessment of sediment-associated HOCs can be significantly simplified: With a method at hand for measuring freely dissolved pore-water concentrations of HOCs, it appears that HOCs' body residues in sediment dwelling organisms can be estimated on the basis of concentrations in pore-water and bioconcentration factors.

Bioaccumulation of LAS in feral fish studied by a novel LC-MS/MS method.

The extent of bioaccumulation of linear alkylbenzene sulfonate (LAS) in feral organisms is presently unknown. To enable LAS determination in biota samples, LAS and its coproducts (methylbranched LAS, dialkyltetralin sulfonates) are extracted from tissues using matrix solid-phase dispersion, isolated by strong anion exchange chromatography and determined by HPLC-electrospray-tandem mass spectrometry. All analytes were quantified in sediment dwelling Tubifex sp. with the sum of the concentrations exceeding 1 micromol/g. Since a portion of LAS was present adsorbed to solids in the guts, the actual body residue was lower than reported lethal LAS body residues. The concentrations of individual constituents in bream muscle samples from the river Saar and fathead minnows caged in the river Arrone ranged up to 2 nmol/g. The apparent bioaccumulation factors in the caged fish are consistently higher than laboratory data, presumably due to a combination of LAS present in the guts adsorbed to suspended material, coingestion of LAS with bacterial detritus, and depressed metabolic activity due to sublethal effects. Given the small deviation between laboratory and field bioaccumulation data and the high detection frequency (> 90%) of C(13)-2- and C13-iso-LAS, the latter two constituents are suitable markers for LAS contamination in fish.

Direct evidence of sequestration in sediments affecting the bioavailability of hydrophobic organic chemicals to benthic deposit-feeders.

In contrast to equilibrium partitioning model (EqP) calculations, biota to sediment accumulation factors (BSAF) of hydrophobic organic compounds for deposit-feeders are highly variable. Recent literature suggests that this variability can be attributed to differences in sequestration or the presence of slowly desorbing fractions in the sediment. In the present study, we investigated whether the observed relationship between bioavailability and sequestration is causal. We determined BSAF values and sequestration status, measured as the distribution over rapidly and slowly desorbing fractions, of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in a manipulated sediment as well as in the original, unmanipulated sediment The manipulation, 48 h suspending with Tenax, resulted in reduction of the rapidly desorbing fraction, while other factors such as contact time and sediment properties remained constant. Contrary to expectations based on EqP, BSAF values did not remain constant but were reduced by a factor of 2-27, proportional to the reduction in rapidly desorbing fractions. The results provide direct evidence of a causal relationship between sequestration and bioavailability to deposit-feeders. Furthermore, the present study demonstrates the need to modify traditional use of the equilibrium partitioning model to account for variation in the sequestration status of HOC in sediments.

Bioconcentration of n-dodecane and its highly branched isomer 2,2,4,6,6-pentamethylheptane in fathead minnows.

Petroleum products are complex mixtures of hydrocarbons. They are important as constituents of fuels and lubricants, and as key raw materials for the chemicals industry. Since there is a potential for accidental releases to the aquatic environment, bioaccumulation of higher hydrocarbons is of concern. Here, the bioconcentration behaviour of two representative hydrocarbons, the dodecane isomers n-dodecane and 2,2,4,6,6-pentamethylheptane (PMH), was investigated in fathead minnows at concentrations in water below their maximum aqueous solubility. The concentration of n-dodecane in fish did not exceed our method limit of detection of 60 microg/kg. In contrast, PMH could be quantified in fish. No significant increase in the ratio of PMH concentrations in fish to water could be detected indicating that an exposure time of 4-10 days is sufficient to approach steady-state. For n-dodecane the upper limit of the bioconcentration factor (BCF) is estimated by dividing the method limit of detection by the exposure concentration and a value of 240 l/kg is derived. For PMH the bioconcentration factor, estimated as the average fish/water concentration ratio during the steady-state part of the experiment, ranges between 880 and 3,500 l/kg. The BCFs of both compounds are small compared to their hydrophobicity. Given that both linear and branched hydrocarbons are known to be biotransformed by fish, it appears that efficient metabolism of the test compounds in fathead minnows prevents bioaccumulation.

The sorption and transport of a sulphonamide antibiotic in soil systems.

Veterinary medicines are administered to animals to treat disease and protect their health. After administration, the substances can be metabolised and a mixture of the parent compound and metabolites may be excreted in the urine and faeces. For animals on pasture, the excreta will be released directly to soil whereas for intensively reared animals, the main route of entry will be through slurry and manure spreading. Whilst the behaviour of other classes of substance (e.g. pesticides and nutrients) that are applied to soil is well understood, limited information is available on the transport and fate of veterinary medicines applied to soils. Laboratory and field studies were, therefore, performed to investigate the sorption behaviour of the sulfonamide antibiotic, sulfachloropyridazine, in soil and to assess the potential for sulfachloropyridazine to move from soil to surface waters and groundwaters. Sorption coefficients (K(D)) for the compound in soil and soil/slurry mixtures were low (ranging from 0.9 to 1.8 l kg(-1)) and indicated that the substance would be highly mobile. Field studies on a clay field supported these observations and demonstrated that, after application, the compound was rapidly transported to surface waters, concentrations of up to 590 microg l(-1) being observed in drainage waters. Leaching studies at a sandy site indicated that the substance had a low potential to leach to groundwaters, concentrations in the soil pore water being below or close to analytical detection limits. An assessment of currently available models for predicting concentrations of veterinary medicines entering surface waters indicated that for sulfachloropyridazine, the methods provide reasonable estimates, predicted concentrations being within a factor of two of the maximum measured concentrations. The approaches may not, however, be appropriate for use on highly hydrophobic substances or for predicting groundwater concentrations.