Draft Technical Guidelines on Paint Reformulation
These Technical Guidelines are developed to help address both capacity constraints and technical barriers to the substitution of lead compounds in paints with focus on SMEs needs for the effective and efficient reformulation of paint.
Paint is defined as a pigmented coating material which, when applied to a substrate, forms an opaque dried film having protective, decorative or specific technical properties. Paints meet very different technical properties like specific chemical or weather resistance, signal or camouflaging effect, decorative effects, insulation or conductive properties, antibacterial properties, etc. Paint is also formulated to adapt to a variety of substrates and methods of application. Since there are many different initial lead-containing formulations for colour and other paint properties, these Technical Guidelines provide only general information on paint reformulation processes. In-depth analyses and more specific data will be provided through pilot demonstrations through the GEF Lead Paint Project to participating companies, according to their specific needs.
Terms related to paints in these Technical Guidelines are in accordance with International Standard ISO 4618:2014.
Paint formulation consists of a large number of components such as binders, additives, plasticisers, fillers and pigments. Paint performance is mainly determined by film-forming raw materials, however, pigments, extenders, additives, proper production processes and methods of application are also important factors to consider. A significant requirement for these components is that they should not be very hazardous to human health and the environment.
Lead compounds in paints (mostly pigments and driers) meet strict technical requirements, but are nevertheless extremely hazardous to the environment and to human health. SMEs should not use any raw materials containing lead and should seek to ensure low levels of lead in raw material ingredients. However, the lead compound alternatives used should have the least hazardous properties possible.
The Technical Guidelines indicate the hazards of lead compounds and their alternatives by referring to the conventions of the Globally Harmonized System of Classification and Labelling of Chemicals4 (GHS). The GHS facilitates the definition and classification of the hazards of chemical products, and communicates health and safety information on labels and safety data sheets. It was developed under the auspices of the United Nations and the goal is to establish a harmonized system to classify hazards, and to develop labels and safety data sheets (SDS) at the global level.
The GHS labelling conventions are used to illustrate hazards and enable SMEs to choose among available alternatives.
The Guidelines start with a short description of the hazardous properties of lead and the lead compounds used in paint formulations (Chapter 4, Section 4.1).
Lead compounds used in paints are extremely hazardous to human health and the environment and should have priority in substitution. Transfer to alternatives should result in reduced overall risks to human health and the environment. Chapter 5 provides guidance on the general approach and steps in the substitution process to help SMEs choose alternatives that are not as hazardous or more hazardous than the lead compounds they wish to substitute.
In addition, to providing colour, forming effects and providing hiding power, there are other technical demands that pigments should meet, including complete insolubility in the surrounding media, good fastness to light and weather exposure, heat resistance, and lack of sensitivity to the effects of chemicals as well as environmental and health safety properties. In Chapter 6, the properties of alternative pigments are presented. The anticorrosion properties of alternative anticorrosive pigments are compared to lead oxide.
The top coat reformulation process usually demands colour matching - brief information on colour theory is presented. To provide orientation on shade functionality, transparency and pigment chroma, a colour comparison of alternatives to PY 34 and PR 104 is presented. Durability, dispersibility, heat stability, bleeding, gloss retention, availability, economic feasibility and environmental, health and safety properties are compared as well.
Since paint colour and properties to a large degree depend on the dispersion process and additives for dispersion, this is also shortly presented in this chapter.
Finally, Chapter 7 provides information on the role and type of driers, and alternatives to lead driers.