4. 1. 1. Limit for the solvent content of bitumen mixtures

VOCs have numerous effects on human health and well-being, ranging from sensory impressions (smell, irritation) already at low concentrations, to toxic long-term effects, which usually occur only at higher concentrations. An important factor here is that part of the low-concentration effects are sensory impressions or other effects that cannot be (fully) examined in the context of animal testing. VOC mixtures may cause non-specific effects even at low concentrations, particularly irritations of the mucous membranes of the eyes and the nose, and the respiratory tract. In addition, exposure may result in non-specific symptoms such as headaches, tiredness, concentration problems, nausea, or elevated body temperature.

The most relevant environmental impact of VOCs, especially in hot midsummer temperatures, is that they may react with nitrogen oxides (primarily from traffic-related emissions), under the influence of sunlight, into humanotoxic photo oxidants (often referred to as “low-level ozone”, or “tropospheric ozone”) that are strong irritants.

Furthermore, the greenhouse potential of VOCs is significantly greater than the potential of carbon dioxide, and their influence on climate change is thus considerable. In its climate protection programme, the City of Vienna has therefore declared the goal of minimising, to the greatest possible extent, solvent emissions arising in the context of construction work.

Bituminous mixtures may be applied cold or hot. In the case of hot application, bitumen is heated over a temperature limit of 80 °C so that bituminous vapours and aerosols (carcinogenic working materials Class 2) may be released ("hot bitumen"). There are two forms of cold application of bituminous mixtures: solvent-based products, around 50% of which consist of crude-oil distillates, and emulsions, which are almost free from organic solvents.

Both types are equivalent with regard to their technical properties. On fresh concrete substrates and under conditions of high ambient humidity, emulsions, which are hydrophilic, have advantages compared to the hydrophobic solvent-based systems. In the case of massively soiled or dirty (e.g. oily) substrates, the situation is reversed. Emulsions cannot be used on metallic substrates, which usually have to be made hydrophobic for production purposes (sheeting), or at low temperatures: near freezing point, the emulsions "break" (i.e. the water separates from the bituminous phase), and it may be impossible to apply an even, fully insulating coat.

As insulation work is usually performed under outdoor conditions, a minimum application temperature of 5 °C is required because wind chill and the coldness of the object have to be taken into account. Analogous conditions are required for the storage of bitumen containers.

As a rule, under wintry outdoor conditions it is hardly possible, or impossible, to use conventional emulsions. Good scheduling of the construction work is thus important too: if it is possible to have insulation work carried out either before or after the winter season, and to postpone insulation work during short periods of low temperature, the majority of solvent emissions can be avoided.

If bituminous emulsions cannot be used, products with the lowest possible solvent content and the smallest health hazards must be used, e.g. products with the lowest possible GISCODE classification under the German GIS information system on hazardous substances.

GISCODE	Type of product	Max. classification (R phrases)	Hazardous constitutents
BBP10	Bitumen emulsions	H317, EUH208, EUH210	In addition to emulsifiers, max. 3% organic auxiliary components such as solvents
BBP20	Low-aromatic bitumen mixtures, with solvents	H226, H315, H319, H336, H412	≤ 25% solvents; hydrocarbon mixture with 1–25% aromatic content
BBP30	Low-aromatic bitumen mixtures, high solvent content	H226, H304, H315, H319, H336, H411	> 25% solvents; hydrocarbon mixture with 1–25% aromatic content
BBP40	Bitumen mixtures, low aromatic content, hazardous to health, with solvents	H226, H302, H312, H315, H319, H332, H336, H412	≤ 25% solvents; hydrocarbon mixture with 1–25% aromatic content
BBP50	Bitumen mixtures, low aromatic content, hazardous to health, high solvent content	H226, H302, H304, H312, H315, H319, H332, H336, H411	> 25% solvents; hydrocarbon mixture with 1–25% aromatic content
BBP60	Bitumen mixtures, high aromatic content, hazardous to health, with solvents	H226, H302, H312, H315, H319, H332, H336, H412	≤ 25% solvents; hydrocarbon mixture with an aromatic content of over 25%
BBP70	Bitumen mixtures, high aromatic content, hazardous to health, high solvent content	H226, H302, H304, H312, H315, H319, H332, H335, H336, H411	> 25% solvent content; hydrocarbon mixture with an aromatic content of over 25%

Bitumen shall generally be used in the form of cold-application bitumen emulsions free from aromatics, with a maximum solvent content of 3% by weight (GISCODE classification BBP10 or equivalent).

Bituminous solutions and hot-application bitumen products are inadmissible.

Solvent-based products must only be used for hydrophobic metallic substrates, and must be available in small containers. If, as in such a case, bituminous emulsions cannot be used, products with the lowest possible solvent content and the smallest health hazards must be used, e.g. products with the lowest possible GISCODE classification under the German GIS information system on hazardous substances.

When hot bitumen is used, care must be taken to ensure that the exposure limit for the resulting bituminous vapours and aerosols of 10 mg/m³ is adhered to during application.

Proof:
Safety data sheet as amended by Regulation (EU) No 453/2010, and manufacturer's declaration.

All products awarded the Blauer Engel/Blue Angel label, and products classified as GISCODE BBP10 meet these requirements.

Alternatively, the corresponding baubook declaration may serve as evidence (www.baubook.info/oea).