Impact of legislation on ink manufacture and usage

CHEMICAL LEGISLATION

The European legislative landscape has been transformed by a complex set of regulations known as REACH – Registration, Evaluation, Authorisation and Restriction of Chemicals. As these regulations also affect products imported into Europe, this will be a major focus of this chapter.

Launched in 2006, REACH is said to be the most complex legislation ever adopted in the EU, with 141 articles, 17 annexes, more than 800 pages. It is legally binding not only in the EU, but also Norway, Liechtenstein and Iceland.

All substances manufactured and imported into the European economic area above one tonne need to be registered. During the registration process, documented information for safe use is communicated along the supply chain.

During the evaluation stage, a check of registration dossiers is carried out by the European Chemicals Agency (ECHA), located in Helsinki, along with associated authorities throughout Europe designated to assist the ECA.

One of the outcomes of this evaluation process is CoRAP, the Community Rolling Action Plan. The CoRAP list contains an updated list of substances going through the evaluation process.

New information can be added at this stage, and information may be challenged by the relevant authorities. An example is Titanium dioxide, currently undergoing assessment as to whether or not it is carcinogenic.

SVHC (Substances of Very High Concern) are partly subject to restrictions and these restrictions will be given according to annexe 17 in the REACH regulation. Another spin-off is harmonized classification. The Classification Labelling and Packaging regulation, which is derived from this, is listed in the annexe VI.

As noted earlier, registration is mandatory above one tonne and has to be done by each individual manufacturer or importer –or the so-called ‘only representative’, which can be designated by the manufacturer. For example, a manufacturer in China can designate an ‘only representative’ in Europe who then registers on behalf of this Chinese supplier.

Registration has to be done regardless of whether the substance is new or well established: the rule is ‘one substance, one registration’. Registration with the ECHA or an authorized affiliated body is a costly process, with registration fees – which depend on the tonnage band – on top of testing costs.

DOWNSTREAM ISSUES

REACH compliance is usually taken care of by the suppliers of the chemicals, but ink manufacturers need to review their chemical inventory and check if all substances used in their products are really registered. This can be checked on the safety data sheet under section three. This guards against the risk that the registration is no longer supported by your supplier and that the product will still be available in the future.

In this case, the REACH registration database can be consulted to check if another supplier has registered the same substances, allowing a switch of suppliers without affecting the product formulation.

May 2018 was the deadline for all substances above one tonne and below 100 tonnes. This was the last of the three registration deadlines. In this band of low tonnage materials, suppliers may decide to quit the registration process for these materials because the costs involved in the registration are too high.

GLOBALLY HARMONISED SYSTEM

In terms of ink packaging, this follow CLP regulations, which themselves follow the Globally Harmonised System. GHS classifies hazards in three groups; physical hazards, health hazards, environmental hazards. There are 29 hazard classes describing the type of danger and the hazard category and severity of hazard. There are nine pictograms and the introduction of key signal words for warning and danger, hazard statements and precautionary statements.

Labels will consist of a product identifier, Hazard and Precaution (‘H’&’P’) signal word (for example ‘danger’) and hazard picttograms. The language has to be the local language.

Converters should evaluate the H & P phrases and inform their workforce, and train them in how to safely handle and store these products. For example, avoid freezing temperatures or avoid storing inks with oxidizing materials.

GHS is a voluntary system and is not universally adopted, particularly in the US. There tends to be a ‘building block’ approach and everybody can pick up the elements which interest them.

The safety data sheet is a very important document and a more comprehensive statement than the label. Since the 1st June 2015, there is a requirement only to use the official CLP and GHS classifications with the new pictograms. Local language is compulsory. It needs to be provided on paper but it can also be provided electronically.

The data sheet should be checked carefully by converters. Converters will be responsible even if a hazard is not indicated properly. If it is ignored and workers in the print plant are exposed and have negative reactions the converter is responsible. For example, where heavy metals are present, this is normally a trace impurity issue and would not normally be found in the safety data sheet. So, the safety data sheet is only one element in a complete safety audit and it is worth asking additional questions of your suppliers. Safety data sheets only have to be supplied under certain conditions: for example, when the substance or mixture is classified hazardous or very persistent, bio-accumulative or on the candidate list for SVHC, or if a non-classified mixture contains certain substances above specified limits.

An important section for converters in the safety data sheet is section eight, exposure controls and personal protective equipment. For example, handling UV inks requires eye and hand protection, and the protective material is also indicated – for example in the case of UV, this needs to be neutral rubber to provide a sufficient barrier property against UV agents.

FOOD CONTACT LEGISLATION

In Europe, the basic principles of food contact legislation are laid out in the EU framework regulation from 2004, No. 1935. These are very basic principles: there shall be no risky migration, no change in  ood composition and no deterioration of food. Applied to labels this means strict limits on permissible limits to ink and adhesive migration. In addition, there are GMP and other specific regulations, especially the 2011, No. 10 plastics in food contact regulations. These set a limit on what is considered risky migration – namely if you exceed a specific migration limit for a certain material and a certain substance.

Similar regulations exist around the world.

Switzerland is unique in having an ordinance specifically applying to packaging inks, and it has become, more or less by default, a global standard because it is promoted by a lot of brand owners.

In addition, converters will have to take into account what individual brand owners require outside the statutory framework.

An example is Nestlé, which has very specific compliance requirements for suppliers on a global scale.

Brand owners continue to be nervous about UV because of some migration scares in the past. For example in 2006 photoinitiator was found to have migrated into fruit juice and baby milk, leading to mass product recalls which impacted Nestlé and Tetra Pak in particular.

And benzophenone was found to have migrated from a sleeve on an HDPE bottle into cream, leading to mass recalls in the Netherlands.

Migration can happen in two ways:

1. Set-off from the print side to the reverse side when PS labels are printed reel to reel, and the inks or coatings subsequently come into contact with food stuff
2. Diffusion, where the container material is not a barrier (plastics), ink components can migrate from the printed surface to the food product.

Low migration ink systems are mandatory for printing on food contact materials, but do not take away the requirement for migration testing. Testing is carried out using a simulated food product, usually ethanol solutions.

The analysis is carried out using sophisticated analytical equipment like LCMS or GCMS.

The amount of migration should be no more than 10 ppb (parts per billion). Once again, there is no global standard methodology for these ink migration tests, so the European Printing Inks Association (EUPIA) has now launched guidance notes on migration testing, and this can be downloaded from its website.

These guidelines are aimed at creating a more scientific discussion around how migration conditions are applied, in order to mimic real-world conditions and to prevent false positive results. Ink manufacturers are encouraged to provide statements of composition which give detailed information about migrants present in the ink so that the convertor and the downstream users in general, including the brand owner, can verify if it is compliant or not.

This allows ‘worst case’ calculation of whether a specific migrant will cause a problem in the specific print, under the specific print conditions, taking into account factors including ink coverage and material grammage etc. This can be done before the print is sent to migration testing, which is costly. 

HEALTH & SAFETY GUIDELINES

Chemicals used in printing inks and lacquers and cleaning solvents are substances that can cause ill health if there is exposure. For example, press operators can breathe in vapors and mists caused when the press is running at high speeds. Contact with chemicals can cause skin problems and chemicals may be absorbed through the skin and cause damage in other parts of the body.

Solvents and inks can irritate the skin leading to dermatitis, while UV inks and laminating adhesives can cause skin allergy and asthma. Some solvent vapors can make workers dizzy, drowsy and affect the central nervous system.

Some solvents can damage internal organs including the liver and kidney if exposure is over a long period.

Converters should follow the locally enforced legal regime for identifying and controlling these hazards when handling inks and varnishes. The goal is to adequately control exposure to materials in the workplace by:

• Identifying which harmful substances may be present

• Deciding how workers might be exposed to them and be harmed

• Looking at what measures are in place to prevent this harm and deciding whether you are doing enough

• Providing information, instruction and training

• In appropriate cases, providing health surveillance

HANDLING SOLVENT INKS

Solvent inks used in gravure and flexo printing present a particular issue in terms of explosion risk, and the risk assessment should take in all areas from ink mixing to ink handling on the press, press dryers and cleaning systems.

The British Standards Institute gives the following advice:

• Avoid low flashpoint solvents such as MEK – substitute with high flashpoint solvents

• Reduce solvent vapor by automated delivery systems and good housekeeping

• Provide local exhaust ventilation (LEV) at the printing units and adequate ventilation in the work room

• Control room temperatures

• Monitor solvent vapor levels to ensure they are 25 percent of LEL (Lower Explosion Limit)

• Carry out a hazardous area classification and ensure fixed equipment within zoned areas is suitably protected and maintained

• Eliminate other sources of ignition such as smoking materials and portable electrical equipment

• Avoid static generation – for example limit liquid flow speeds, provide earth bonding, anti-static additives and footwear

• Minimize risk of spread of fire by segregating printing, storage and other areas and ensuring mixing of solvent-based inks is carried out in a dedicated fire resisting room

• Provide dampers to isolate solvent recovery units in the event of fire

• Design Dryers to BS EN 1539:2009. Earlier dryers should meet BS EN 1539:2000 or if older have safety features including shut off valves, ignition systems, flame failure devices, purging explosion relief

• Check annually the solvent vapor levels within dryers.

HANDLING UV INKS

Safe handling of UV inks also requires detailed attention. As soon as a UV ink is exposed to a UV light source, an instantaneous chemical reaction takes place which presents potential dangers if the ink is inhaled or gets onto the skin. Skin contact with UV-curable inks and coatings may cause dermatitis. Most at risk are ink mixers, press operators and cleaning operatives.

The advice of the British Standards Institute is:

• Provide splash-resistant gloves

• Screen UV curing units with fixed or interlocked covers to avoid leaks of UV light

• Set up the machine to avoid ink misting. Use mist extraction or shroud the rollers to trap the mist

• Consider using water-cooled UV lamps as these generate less ozone

• Wire in ozone extraction to the UV lamp power supply

• Air-cooled lamps require an inward airflow between 0.5 and 1 meter per second at openings

• To reduce ink mist requires an airflow between 1 and 2.5 meters/second into openings

• Fit a manometer or pressure gauge to show that extraction is working.

Although respiratory protective equipment (RPE) should not be needed for routine use, splash-resistant gloves should be provided where there is a risk of skin contact – single-use nitrile gloves 0.2 mm thick are acceptable.