Analysis of the environmental performance and toxicity of epoxy floor coatings

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Regarding the environmental performance and toxicity of floor coatings, the situation is as follows: I. Solvent-based floor coatings – Key components and information on toxicity: 1. Epoxy resin and curing agents: Epoxy resin and curing agents are toxic when used alone, but the cured product resulting from their reaction is non-toxic and meets FDA’s toxicity requirements. 2. Pigments and fillers: Some pigments and fillers contain toxic components such as heavy metals, for example chromium yellow; whereas others are non-toxic, such as food-grade titanium dioxide, iron oxide red, iron oxide yellow, talcum powder, quartz powder, etc. For coatings that are required to be non-toxic after drying, non-toxic pigments and fillers can be used, avoiding those that contain toxic substances such as heavy metals; however, this limits the colors available for such coatings, and the cost of certain colors increases. 3. Solvents: Most solvents are harmful to the human body, but their toxicity varies, and the degree of residue they leave in the coating also differs. During construction and the drying of the paint film, solvent evaporation can be harmful to the environment and human health; it is therefore advisable to use solvents that cause less harm to humans and to improve ventilation in order to reduce concentrations. For the dried coating film, if the solvent used has low residual properties, the solvent essentially evaporates completely, causing no harm to the environment or human health. 4. Additives: The amount of additives in the coating film is very small. Additives with high toxicity are no longer used, so their toxic impact on the coating film is minimal. II. Solvent-Free Floor Coatings: Categories, Main Components, and Toxicity Information Solvent-free epoxy sealing primer: 1. Epoxy resin and curing agent – Epoxy resin and curing agent are toxic when used separately, but the cured product resulting from their reaction is essentially non-toxic and meets FDA toxicity requirements. Solvent-free epoxy intermediate mortar: It is composed of epoxy resin, a curing agent, quartz sand, and quartz powder. Epoxy resin and the curing agent are toxic when used alone, but the cured product resulting from their reaction is non-toxic and meets FDA toxicity requirements ； Quartz powder and quartz sand: These are products obtained by crushing and screening natural minerals; their main component is silicon dioxide, and they are basically non-toxic. Solvent-free epoxy self-leveling topcoat: 1. Epoxy resin and curing agent ； Epoxy resin and curing agent are toxic when used alone, but the cured product resulting from their reaction is non-toxic and meets FDA toxicity requirements. 2. Pigments and fillers: Some pigments and fillers contain toxic components such as heavy metals, for example chromium yellow; while others are non-toxic, such as titanium dioxide, iron oxide red, iron oxide yellow, talc, quartz powder, etc. For coatings that are required to be non-toxic after drying, non-toxic pigments and fillers can be used, avoiding those that contain toxic substances such as heavy metals; this limits the range of colors available for such coatings, and the cost of certain colors increases as a result. 3. Additives: The amount of additives in the coating film is very small. Additives with high toxicity are no longer used, so they have little toxic impact on the coating film. In summary, floor coatings can indeed be made to be environmentally friendly and non-toxic. However, it cannot be said that all floor coatings produced by manufacturers are non-toxic. To the best of my knowledge, heavy metal pigments such as chrome yellow and chromium oxide green are widely used in floor coatings. In particular, some small-scale manufacturers, due to limited technical capabilities, are unable to address the problem of discoloration and mottling that can occur when organic pigments are used. Moreover, some non-toxic organic and inorganic pigments are expensive. It is easier to use solvent-free primers, intermediates, and topcoats (as solvent-based products leave some residual solvents behind); by using a solvent-free self-leveling topcoat and selecting non-toxic pigments and additives during production, it is possible to make the entire coating non-toxic. For the toxicity testing of coatings, it is possible to entrust health and epidemic prevention departments to conduct the tests; the common testing methods include the following: 1. After the coating has cured, use the coating powder in feeding trials on white rats. 2. Coat the container with paint, wash it after it dries, and then fill it with water to test raising goldfish. 3. Coat the container with paint, clean it after it dries, soak it in distilled water for a while, and then test whether the water quality meets drinking water standards. 4. Test whether the heavy metal content in the coating exceeds the specified limits (measurement can be carried out in accordance with ASTM 961-96A or EN-71 standards).