The sector “Solvent and Other Product Use” covers paint application, degreasing and dry cleaning, chemical products and other product use. This section presents NMVOC, N₂O and CO₂ emissions from use of solvents and other products in industrial processes and households and pollutants emitted from use of fireworks.

Solvents are chemical compounds, mainly comprising of NMVOCs, which are used on a global scale in industrial processes and as constituents in final products to dissolve e.g. paint, cosmetics, adhesives, ink, rubber, plastic, pesticides, aerosols or are used for cleaning purposes, i.e. degreasing. In industrial processes where solvents are produced or used NMVOC emissions to air and as liquid can be recaptured and either used or destroyed. Solvent containing products are used indoor and outdoor and the majority of solvent sooner or later evaporate. A small fraction of the solvent ends up in waste or as emissions to water and may finally also contribute to air pollution by evaporation from these compartments.

Although NMVOCs are not considered direct greenhouse gases, their role as precursors in tropospheric ozone formation, which is a greenhouse gas, further justifies their inclusion in a greenhouse gas inventory. Furthermore, once emitted to the atmosphere NMVOCs react with reactive molecules, such as HO-radicals or UV-light, eventually resulting in the formation of CO₂. Although the CO₂ contribution is relatively small compared to emissions from combustion of fossil fuels, waste and traffic, solvents are included in the national GHG emission inventories and are estimated to ensure the fulfilment of NMVOC emissions ceilings (Directive 2001/81/EC). In relation to toxicity some NMVOCs may be harmful towards humans and/or the environment. In addition to high-volume NMVOCs, i.e. chemicals used in amounts over 1000 tonnes pr. year, also high frequency low dose exposure of low volume NMVOCs, as part of daily activities and use of consumer products, may show to be critical.

Emission inventories for solvents are based on model estimates, as direct and continuous emissions are only measured from a limited number of pollutants and sources. For each source emission estimates are based on relationships between activity data and emission factors (emissions pr unit activity), often assuming a linear model by multiplying activity data with appropriate emission factors. Activity data are derived from various sources, e.g. Statistics Denmark or industrial sectors. Emission factors are either based on guideline default values, international recommendations or on knowledge from industrial processes and technologies in the various sectors. The method that is used allows for use of CO₂ conversion factors for specific chemicals, thus enabling a more exact calculation of the national CO₂ emissions.

The figure below shows emissions of NMVOC from 1985 to 2009, where the used amounts of single chemicals have been assigned to specific main reporting sectors. A linear extrapolation is made for the period 1985–1994. A general decrease is seen throughout the sectors. Solvent use constitutes approximately one third of the total NMVOC emissions, i.e. 27.351 tonnes in 2009 and represents 64.400 tonnes CO₂-equivalents, which constitutes 0.1 % of the total Danish CO₂ emissions. NMVOC emissions have decreased with 57 % in the period 1985 to 2009

The most abundantly used NMVOC as solvent are ethanol, turpentine (white spirit defined as a mixture of stoddard solvent and solvent naphtha) and propylalcohol. Ethanol is used as solvent in the chemical industry and as windscreen washing agent. Turpentine is used as thinner for paints, lacquers and adhesives. Propylalcohol is used in cleaning agents in the manufacture of electrical equipment, flux agents for soldering, as solvent and thinner and as windscreen washing agent. Household emissions are dominated by propane and butane, which are used as aerosols in spray cans, primarily in cosmetics. Higher emission factors are applicable for diffuse use of solvent containing products e.g. in households and lower emission factors are applicable for use in industrial processes.

Emissions of NMVOC in ktonnes pr year (equal to Gg pr year). Linear extrapolation is made for 1985 – 1994. Click here for background data.

Five companies sell N₂O in Denmark and only one company produces N₂O. N₂O is primarily used in anaesthesia by dentists, veterinarians and in hospitals and in minor amounts as propellant in spray cans and in the production of electronics. Due to confidentiality no data on produced amount are available and thus the emissions related to N₂O production are unknown. An emission factor of 1 is assumed for all uses, which equals the sold amount to the emitted amount. Sold amounts are obtained from the respective companies and the produced amount is estimated from communication with the company.

Total sold and estimated produced N₂O for sale in Denmark, which equals the emissions, is 0.109 Gg N₂O in 2009.

FIREWORKS

The use of fireworks is comprised in Other Product Use. In the Danish emission inventory system emissions from combustion of fireworks are treated individually according to source.

Pollutants emitted from the combustion of fireworks are SO₂, CH₄, CO, CO₂, N₂O, particulate matter (PM), heavy metals (HM; As, Cd, Cr, Cu, Hg, Ni, Pb, Zn),

The calculations are based on the annual aggregated import/export data and hence assumes that cross-border shopping, local production and use of illegal fireworks to be negligible

Figure 1   Time-series of activity data for consumption of fireworks for the years 1990-2009

The greenhouse gas effect from fireworks is from CO₂, CH₄ and N₂O emissions. The contribution to CO₂-eqv. emissions is for the time-series 1990-2009 below 0.006 % of the total national emission. The trend for the total emissions 1990 - 2009 from this source is increasing; compared to 1990 the 2009 emission is 321 % higher.

The most important pollutants in the category of consumption of fireworks are Cr and Cu. This category makes up for 11.0 % and 4.9 % of the national emissions of Cr and Cu respectively.