Abstract  National generation estimates for seven material types in the construction and demolition debris stream are regularly published in the United States. However, the quantities of these materials in different end-of-life management pathways are not published or otherwise made available. Quantification of end-of-life management pathways is useful for identifying approaches to decrease disposal and increase material recovery. An issue for construction and demolition debris is that data needed for a nationwide estimate of management pathways are not tracked in a single system. We propose and outline a method that draws on a combination of data sources, including nationwide generation estimates, state data, industry association data, and recovery facility reports. Capturing the available data and using the proposed method, we can estimate what end-of-life pathways are used for the seven materials in the US Environmental Protection Agency’s annual reports of CDD generation (steel, wood products, drywall and plaster, brick and clay tile, asphalt shingles, concrete and asphalt concrete), and five additional materials managed within the CDD waste stream (carpet, plastic, glass, cardboard and organics). Method results indicate that the vast majority of CDD concrete and asphalt pavement, which in 2014 constituted ∼78% of the overall mass of the stream’s components, were reclaimed for use, primarily in road projects. A significant opportunity for material recovery still exists for the remaining ∼22% of the stream. In 2014, approximately 64% of these remaining materials in the US was ultimately routed for landfill disposal.

Abstract  In this criteria document, the National Institute for Occupational Safety and Health (NIOSH) reviews the critical health effects studies of hexavalent chromium (Cr(VI)) compounds in order to update its assessment of the potential health effects of occupational exposure to Cr(VI) compounds and its recommendations to prevent and control these workplace exposures. NIOSH reviews the following aspects of workplace exposure to Cr(VI) compounds: the potential for exposures (Chapter 2), analytical methods and considerations (Chapter 3), human health effects (Chapter 4), experimental studies (Chapter 5), and quantitative risk assessments (Chapter 6). Based on evaluation of this information, NIOSH provides recommendations for a revised recommended exposure limit (REL) for Cr(VI) compounds (Chapter 7) and other recommendations for risk management (Chapter 8).

Abstract  Atmospheric and aquatic emission load of hexabromocyclododecane (HBCD) for the period 1986-2030 were estimated by substance flow analysis. Through the investigation of quantitative HBCD life cycle, estimated HBCD stock in the use phase shows a continuous increase, indicating that emissions from the materials containing HBCD will be potentially long-term sources of pollutants leaching or volatizing to the environment. In Japan, 571 kg/year and 41 kg/year of HBCD was calculated to emit to the atmospheric and aquatic environment in 2000, respectively. This corresponds to 0.03 % of the consumed HBCD quantity in Japan. These environmental emissions of HBCD were increasing rapidly until 2011. On the other hand, decreasing trend for HBCD were estimated between 2012 and 2030 and the emissions were simulated to be as high as 225 kg/year in 2030. This is due to the scenario that the use of HBCD for textiles would be stopped. The largest component of the emissions is simulated to be into the atmosphere from the consumer product because the stock in the use phase has been growing over the whole period. The source profile of environmental emission would shift from upstream to downstream of product chain. The present study gives an insight to obtain basic information for long term measures toward strategic chemical management considering their life cycle.

Abstract  Pursuant to section 74 and 68(b) of the Canadian Environmental Protection Act, 1999 (CEPA 1999), the Ministers of the Environment and of Health have conducted a screening assessment of hexabromocyclododecane (HBCD). HBCD having Chemical Abstracts Service Registry Number 3194­55-6 was one of the substances on the Domestic Substances List (DSL) selected for a pilot project for screening assessments. During the categorization of the DSL, the substance was identified as a high priority for screening assessment as it met the criteria for persistence, bioaccumulation and inherent toxicity to aquatic life. It is recognized that the Chemical Abstracts Service (CAS) registry contains more than one number for HBCD (e.g., CAS RN 25637-99-4 refers to HBCD where the bromine substituents are not numbered). In this assessment, all available relevant data and studies that are of reliable quality were considered equally, and thus the assessment findings and scope apply to HBCD in general and are irrespective of the Chemical Abstracts Service Registry Number (CAS RN). The primary application of HBCD is as a flame retardant in polystyrene foams that are used as thermal insulation materials in the construction industry. A second application is the flame retarding of textiles for usage in residential and commercial upholstered furniture, transportation seating, wall coverings and draperies. Minor uses include addition to latex binders, adhesives, and paints and to high-impact polystyrene and styrene-acrylontrile resins for electrical and electronic equipment. For the years and continents having available data since 2000, increases in the demand for HBCD have been reported. Global demand for HBCD was estimated at 16 700 tonnes in 2001, representing 8.2% of total demand for brominated flame retardants that year. Results from a section 71 Notice with Respect to Certain Substances on the Domestic Substances List (DSL) conducted for the year 2000 indicated that HBCD was not manufactured in Canada at that time. Amounts imported into the country in that year were in the range of 100 000 to 1 000 000 kg.

Abstract  Most studies of potentially hazardous substances focus on aspects of their occurrence and fate in the environment (monitoring and modelling studies) to estimate the environmental impact and the potential exposure of humans. In order to evaluate emission sources, to recognise environmental impacts at an early stage, and to take efficient legislative or technical measures, it is essential to know their behaviour in the anthroposphere as a function of time. So far, only very few investigations of this type exist for chemicals. In regular risk assessments, only rather limited knowledge is available concerning the behaviour of chemicals in the anthroposphere (production data, substance quantities in products, recycling rates, emissions occurring during use, etc.) or their lifecycle, and no information at all about their behaviour as a function of time. For this reason, it is these aspects that were investigated in a case study within the framework of the national research programme NRP50 for selected brominated flame retardants with endocrine-disrupting potential (pentabromodiphenyl ether, hexabromocyclododecane) or the potential to degrade to such substances (decabromodiphenyl ether). A dynamic substance flow analysis (SFA) model was performed for Switzerland for the time period 1980-2020. In this review paper (a) we present a summary of typical results (system overview, consumption trends/application patterns, anthropogenic stocks and their changes, emission trends including major sources and environmental fate), (b) we summarize the effectiveness of recent risk-reduction measures in Switzerland and (c) we indicate serious remaining data gaps and recommend further important measures for risk reduction. For the future, we suggest improving the knowledge of the lifecycle of chemicals such as brominated flame retardants by applying SFA as a suitable tool to weight the effect of substance flows with respect to environmental emissions, and to serve as the basis for planning actions and measures to reduce such emissions. This is in line with one major conclusion of the NRP50 consensus platform 'Brominated Flame Retardants'.

Abstract  Dermal exposure needs to be addressed in regulatory risk assessment of chemicals. The models used so far are based on very limited data. The EU project RISKOFDERM has gathered a large number of new measurements on dermal exposure to industrial chemicals in various work situations, together with information on possible determinants of exposure. These data and information, together with some non-RISKOFDERM data were used to derive default values for potential dermal exposure of the hands for so-called 'TGD exposure scenarios'. TGD exposure scenarios have similar values for some very important determinant(s) of dermal exposure, such as amount of substance used. They form narrower bands within the so-called 'RISKOFDERM scenarios', which cluster exposure situations according to the same purpose of use of the products. The RISKOFDERM scenarios in turn are narrower bands within the so-called Dermal Exposure Operation units (DEO units) that were defined in the RISKOFDERM project to cluster situations with similar exposure processes and exposure routes. Default values for both reasonable worst case situations and typical situations were derived, both for single datasets and, where possible, for combined datasets that fit the same TGD exposure scenario. The following reasonable worst case potential hand exposures were derived from combined datasets: (i) loading and filling of large containers (or mixers) with large amounts (many litres) of liquids: 11 500 mg per scenario (14 mg cm(2) per scenario with surface of the hands assumed to be 820 cm(2)); (ii) careful mixing of small quantities (tens of grams in < 11): 4.1 mg per scenario (0.005 mg cm(-2) per scenario); (iii) spreading of (viscous) liquids with a comb on a large surface area: 130 mg per scenario (0.16 mg cm(-2) per scenario); (iv) brushing and rolling of (relatively viscous) liquid products on surfaces: 6500 mg per scenario (8 mg cm-2 per scenario) and (v) spraying large amounts of liquids (paints, cleaning products) on large areas: 12 000 mg per scenario (14 mg cm-2 per scenario). These default values are considered useful for estimating exposure for similar substances in similar situations with low uncertainty. Several other default values based on single datasets can also be used, but lead to estimates with a higher uncertainty, due to their more limited basis. Sufficient analogy in all described parameters of the scenario, including duration, is needed to enable proper use of the default values. The default values lead to similar estimates as the RISKOFDERM dermal exposure model that was based on the same datasets, but uses very different parameters. Both approaches are preferred over older general models, such as EASE, that are not based on data from actual dermal exposure situations.