Green Printing Handbook Explained: Raw and Auxiliary Material Compliance for Printing Enterprises and Products

(1) Requirements for printing raw and auxiliary materials

Restrictions on phthalate esters

Phthalate esters (phthalateesters, PEs) are fat-soluble synthetic organic compounds. Among them, di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and butyl benzyl phthalate (BBP) are low-molecular-weight phthalate esters with a carbon content of 8 or below; they pose varying health risks and are a class of environmental pollutants. As important additives in plastics, rubber, coatings, and other chemical products, they are widely used.

Phthalate esters are regulated under relevant EU directives and standards, US consumer product regulations, and other rules. Key regulatory directives and standards include 《BSEN14372：2004》, 2005/84/EC, the Consumer Product Safety Improvement Act H.R.4040, and CaliforniaAB1108.

Printing companies do not directly use phthalate esters and are passive recipients. Therefore, the approach does not require companies to control phthalate ester content in raw and auxiliary materials themselves; instead, control is achieved through the requirements companies place on raw material suppliers. An analysis of the main raw and auxiliary materials used in printing shows that materials possibly involving phthalate esters include inks, varnishes, blankets, and adhesives. Accordingly, the Technical Requirement for Environmental Labeling Products - Printing Part: Lithographic Printing sets restrictions on these four material categories.

Paper brightness (whiteness) requirements

Lowering paper brightness (whiteness) can reduce the amount of pulp bleaching agents and the number of bleaching stages, cut the use of brightening agents and other chemicals, and thereby lower pollutant emissions. At the same time, paper that is too white can also have adverse effects on human health.

Existing domestic requirements for paper brightness (whiteness) mainly involve 3 standards.

1. GB/T17934.2-1999, Printing technology - Process control for the manufacture of half-tone colour separations, proof and production prints - Part 2: Offset lithographic processes. Brightness (whiteness) provisions are shown in Table 2.
2. GB/T18359-2001, Paper and printing quality requirements and inspection methods for primary and secondary school textbooks. Brightness (whiteness) provisions are shown in Table 3.
3. GB/T24999-2010, Paper and board - High limit of brightness (whiteness). Brightness (whiteness) provisions are shown in Table 4.

At present, paper brightness (whiteness) requirements are mainly the responsibility of paper mills, while printing companies only put forward demand. Therefore, in selecting standards, the requirements of GB/T24999-2010, Paper and board - High limit of brightness (whiteness), are referenced. Because primary and secondary school textbooks are controlled by a dedicated standard, their standard basis is GB/T18359-2001, Paper and printing quality requirements and inspection methods for primary and secondary school textbooks. Since brightness (whiteness) provisions have a major impact on current printing product quality, the Technical Requirement for Environmental Labeling Products - Printing Part: Lithographic Printing does not tighten them.

Requirements for lithographic printing inks

Lithographic (offset) printing inks are an important source of environmental pollution in printing and printed products. Inks pollute the environment and harm human health during printing; organic residues on printed products continue to pollute the environment, and these organic residues and harmful substances they contain, including lead, mercury, arsenic, and chromium, also continue to harm the health of printed product users. For this reason, the Technical Requirement for Environmental Labeling Products - Printing Part: Lithographic Printing requires that all inks used in printing environmental labeling products meet the HJ/T370 standard.

Requirements for varnishes

Varnish is a colorless transparent coating and has two functions:

① As a transparent protective coating, its hardness and wear resistance are higher than ...