Holliday Pigments produce over 65% of the world's technical quality Ultramarine pigments. These are inorganic compounds which are the synthetic equivalent of the semi-precious mineral, lapis lazuli. Blue, violet and pink Ultramarine pigments are used to colour plastics, paints, coatings, cosmetics and artists' paints.

Waste gases produced in the manufacture of the Ultramarine pigments contain the acid rain gas sulfur dioxide. An £11million Flue Gas Desulfurisation plant captures the sulfur dioxide and has reduced Holliday Pigment's SO₂ emissions by 99.7% from 6,300 tonnes to only 25 tonnes per year.

A by-product of the desulfurisation process is sulfuric acid. This can be sold to fertiliser manufacturers who use it to produce ammonium sulphate.

The conversion of sulfur dioxide to sulfuric acid is an exothermic reaction. This generates heat which can be used to produce steam. This means that an existing gas-fired boiler can be shut down, saving over £60,000 a year in energy costs and also reducing emissions of the greenhouse gas carbon dioxide to the atmosphere.