Have a UV/EB question? Please check out some of our inquiries and responses below.
Special thanks to Ronald Golden, FocalPoint Consulting LLC, for preparing responses.
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We’re looking to get a definition of “low migration” vs. “low extractables.”
|“Low Migration” is a more meaningful term when claiming suitability for use in food contact packaging. “Extractables” are the labile substances capable of migrating into food or beverages. Even when all of the components of an ink, coating, adhesive, or plastic are listed in the applicable sections of the Code of Federal Regulations Title 21: Food & Drugs, certain quality control tests may be attached to the use of those components. Some of those tests require that the total weight of generic “extractables” per unit area of the packaging must be below a specified limit (typically below 0.5 milligram per square inch), depending on the type of food and conditions of use. It is assumed that all of those “extractabes” could migrate into food or beverages, so this type of packaging could not be considered to support a claim of “low migration”, even though it is fully compliant with the applicable FDA regulations.|
A definition of “low migration” depends on the type of food, the packaging material, the conditions under which the food will be filled into the package, the storage conditions, and whether or not the food will be heated in the package. For each of these parameters, FDA specifies the type of solvent (‘food simulant”), time and temperature for extraction testing to determine the amount of material that could migrate into food or beverages. Details on these specifics can be found in the FDA’s Guidance for Industry: Preparation of Premarket Submissions for Food Contact Substances: Chemistry Recommendations
http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/FoodIngredientsandPackaging/ucm081818.htm, which contains instructions on how to test for migrating substances and how to use the resulting data in calculations to confirm that the concentration of migrating “extractable” substance is below the maximum allowed in food. Individual FDA Food Contact Notifications (FCN) http://www.fda.gov/Food/FoodIngredientsPackaging/FoodContactSubstancesFCS/ucm116567.htm also may specify limits on the maximum amount of material cleared to migrate into food and the required test method.
If the migrating substance is not listed in the 21 CFR sections or in a cleared FCN, then extraction studies conducted as specified in the Chemistry Recommendations must demonstrate that any chance of migration into food is below the “Threshold of Regulation” http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/FoodIngredientsandPackaging/ucm081833.htm. Those studies can be used to support a claim of “low migration”.
What are the FDA considerations when there is potential transfer into food via set-off...
What are the FDA considerations when there is potential transfer into food via set-off to the food contact side in the reel or stack of printed material? Is there a certain "migration limit" for substances not cleared under FDA CFR 21 and for which no toxicological data is available?
The migration limit requirements for FDA cleared materials are specified in each corresponding 21 CFR listing and in the individual FCNs. However, the "functional barrier" exemption applies only to the design of the food package, with the reasonable expectation that the barrier prevents migration of substances from the outside of the barrier into food.
However, packaging materials often are rolled up or stacked one inside the other, so that there can be offset between a printed/coated side of the packaging material and the other, food contact side. If the migrating substance is cleared under an existing FDA regulation, then the specified migration limit must be respected. This can be confirmed by appropriate testing (see below).
If the front-to-back migrating substance is not cleared under an existing FDA regulation, and if it is not a carcinogen or reproductive toxin or other problematic substance, then it still can be used in food packaging if it can be shown by test data or calculations that it would be present "in the diet" at a concentration of 0.5 ppb or less. Below this de minimis concentration the substance is not considered to be a food additive under the "threshold of regulation" principle. Calculations to determine the concentration in the diet can be found in section IIE of FDA Guidance for Industry: Preparation of Premarket Submissions for Food Contact Substances: Chemistry Recommendations at http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/FoodIngredientsandPackaging/ucm081818.htm. In general, if the concentration of the migrating uncleared substance in food is below 50 ppb, then the eventual concentration in the diet normally will be less than 0.5 ppb.
Highly cross-linked coatings over printed surfaces can act to minimize such front-to-back migration. If a coating is not practical, then non-FDA inks should be UV/EB cured or heat set to "lock in" any potentially migrating substances.
In any case, if a printer is concerned about possible front-to-back migration, then appropriate testing of the food contact surface should be conducted to identify and quantify potential migrating substances. Test methods must be validated to assure that they are capable of detecting the target substance at the required low level of migration.
What do I need to know about uv curing formulations and skin irritation?
|The acrylates used in UV curing formulations may cause skin irritation, so nitrile gloves and protective clothing should be worn at all times when handling these materials. Simple latex gloves are not sufficient. Barrier creams may be applied before working with acrylates to facilitate complete skin cleansing during wash-up. If unexpected or accidental contact occurs, the UV curing materials should be washed off of skin with soap and water when the skin contamination is discovered. Contaminated clothing should be laundered or discarded. The slowness for symptoms to develop and the relative mildness of the symptoms in most people can cause many to ignore or delay cleanup. In some cases, repeated exposure caused by poor hygiene practices ultimately can result in enhanced sensitivity to the chemistry.|
In very rare cases for hyper-sensitized people, preventing direct contact with the liquid formulation no longer is sufficient to prevent the irritation reaction, and the only remedy may be to permanently remove them from areas where acrylates are in use. The best way to test whether someone is hyper-sensitized is to determine if they have a reaction after a few minutes just by walking into the UV/EB production area, even without handling or contact with acylate materials. If there is no reaction from just being present in the work area, protective equipment and more attention to good hygiene practices should be adequate to prevent irritation symptoms.
Are nitrile gloves adequate protection from exposure to UV light in the workplace?
|With normal shielding of UV curing equipment, workers are exposed only to reflections of UV light, and normal work clothing provides adequate attenuation of UV radiation in the workplace. Most polymers and pigments are strong absorbers of UV radiation, so even a thin layer of pigmented nitrile rubber is very effective protection from UV light, which does not have much penetrating power. Even unpigmented gloves should provide adequate protection from reflected UV light. Of course, worker training to use the correct protective equipment and to recognize the symptoms of over-exposure is essential. The symptoms of over-exposure to UV light are the same as sunburn, so workers will notice very quickly if their protective gloves or clothing are inadequate for conditions, and you can enhance the protection if necessary. |
What is the role UV and EB technology may play in efforts to develop cleaner technologies that reduce greenhouse gas emissions?
|In 2005, the RadTech Technical Committee weighed-in on the issue with the following observations:|
- UV/EB technology can be a “one-stop shop” for businesses to keep up with state, national and international requirements. Adoption of UV/EB processes can assist compliance with U.S. regulations as well as with those that businesses face abroad.
- The EPA and local air districts agree that UV/EB is good news for the environment. The overwhelming majority of UV/EB coatings, inks and adhesives contain little or no volatile solvent. Solvents, when incinerated, generate additional greenhouse gases from combustion.
- Emissions of VOCs, which are tropospheric (ground-level) ozone precursors, can be nearly eliminated with the use of UV/EB technology. Ground-level ozone is estimated by the EPA to be the third largest contributor to climate change.
- As one example of the savings that has already been achieved through the use of the technology, a major industry study of a UV process line found an over 65% reduction in greenhouse gas emissions. The study compared UV curing to a water-borne coating line equipped with incineration. There was also a documented 80% reduction in the total amount of energy used by the facility. As a result of these energy efficiency advances, the study noted that the energy savings offered by UV/EB technology translated into 62 billion BTU/year for the company, and achieved as much as a 55% reduction in capital and installation costs over thermal curing. While the benefits of UV/EB technology may vary depending on the particular facility and the intended use of the technology, this study and the experience of this industry demonstrate that EB and UV curing may be used to achieve meaningful voluntary reductions of greenhouse gas emissions.
- The use of UV/EB-curing processes can inherently reduce greenhouse gas emissions by reducing reliance on the burning of fossil fuels. UV/EB technology is highly energy efficient, utilizing equipment that is relatively cooler and smaller than that used for other drying methods. In addition, it can cure materials at or near room temperature in a matter of seconds or less. For these reasons, the total energy used in UV/EB-curing processes can be significantly lower than the energy needed for thermal drying, resulting in energy savings and reduced reliance on the burning of fossil fuels that contribute to greenhouse gas emissions.
We are formulating inks for a label on the outside of a plastic cup. The label reaches all the way to the top lip of the cup, so it is likely that the person drinking from the cup...
|We are formulating inks for a label on the outside of a plastic cup. The label reaches all the way to the top lip of the cup, so it is likely that the person drinking from the cup will physically have their mouth in contact with the label and will ingest some of the liquid contents that have come into contact with the outside of the printed label. Is this a direct food contact application, and must the printing on the label be cleared under the FDA regulations for direct food contact?
There are two possible answers, depending on the intended use for the cup.
1. If the labeled cup is used as food or beverage packaging, it is reasonable to expect that substances that have the potential to migrate from the label will be ingested by mouth contact along with the food, and any inks, coatings or adhesives used to manufacture the label must be FDA compliant. They must meet any applicable requirements for composition and extraction testing, or it must be shown that any migration of uncleared component substances is below the level of regulatory concern.
2. If the labeled cup is intended for use solely as a household container, it may fall under the “FDA housewares” exemption, which holds that materials used to manufacture empty containers, dinnerware, eating utensils or appliances sold to consumers for home use do not require food additives clearance.
In both cases, it is advisable to obtain legal confirmation that the inks, coatings or adhesives used to manufacture the label and the finished article comply with all regulations that apply for the intended use.
Is there an established test method for the analysis of VOC/solids of UV coatings and inks?
|Until recently the ASTM D-5403 test method was the accepted standard test method for determining the VOC content of UV/EB curing materials. Test Method D-5403A is applicable to radiation curable materials that are essentially 100% reactive but may contain traces (no more than 3%) of volatile materials as impurities or introduced by the inclusion of various additives. Test Method D-5403B is applicable to all radiation curable materials but must be used for materials that contain volatile solvents intentionally introduced to control application viscosity and which are intended to be removed from the material prior to cure. You can purchase a copy of this standard at http://www.astm.org/Standards/D5403.htm.|
Recently, a RadTech ad hoc Committee developed a new test method that is particularly suited to thin films of applied wet coating (please contact RadTech for more information). This method is currently under review by ASTM.
We are applying coatings to the inside of metal food storage tanks, but a preferred primer is not FDA compliant...
|We are applying coatings to the inside of metal food storage tanks, but a preferred primer is not FDA compliant. Can we apply a UV curable coating that complies with FCN 772 over the primer as a functional barrier to comply with FDA regulations?
A functional barrier must assure that any potential migration of FDA non-compliant substances not in contact with food or beverages is below the “Threshold of Regulation”, i.e. less than 50 ppb in the food. If a coating that complies with FCN 772 is to function as a functional barrier, it must meet three criteria:
1. The UV cured coating must meet all of the composition and extractable monomers and total extractable solids requirements of FCN 772.
2. The UV cured coating must demonstrably prevent migration of any of the uncleared primer components into the food at levels above 50 ppb.
Both of these requirements must be demonstrated by conducting extraction tests with appropriate food simulants as specified in Appendix II, SELECTED MIGRATION TESTING PROTOCOLS, at the FDA Preparation of Premarket Submissions for Food Contact Substances: Chemistry Recommendations web site http://www.cfsan.fda.gov/~dms/opa3pmnc.html#aii.
3. The UV coating must reasonably be expected to continue to serve as an effective functional barrier over the lifetime of the manufactured article (food storage tank).
The design of the tank for the intended application, the compositions of the primer and coatings, and the design and results of the extraction testing protocols and results should be subjected to qualified legal review to assure compliance with FDA regulations
Does RadTech have any information on the proper disposition of 100% solids UV/EB waste?
|By definition, EPA determined that some specific wastes are hazardous. These wastes are incorporated into lists published by the Agency and are organized into three categories:|
1. The F-list (non-specific source wastes). This list identifies wastes from common manufacturing and industrial processes, such as solvents that have been used in cleaning or degreasing operations. Because the processes producing these wastes can occur in different sectors of industry, the F-listed wastes are known as wastes from non-specific sources. Wastes included on the F-list can be found in the regulations at 40 CFR §261.31 .
2. The K-list (source-specific wastes). This list includes certain wastes from specific industries, such as petroleum refining or pesticide manufacturing. Certain sludges and wastewaters from treatment and production processes in these industries are examples of source-specific wastes. Wastes included on the K-list can be found in the regulations at 40 CFR §261.32 .
3. The P-list and the U-list (discarded commercial chemical products). These lists include specific commercial chemical products in an unused form. Some pesticides and some pharmaceutical products become hazardous waste when discarded. Wastes included on the P- and U-lists can be found in the regulations at 40 CFR §261.33 .
Waste that have not been specifically listed may still be considered a hazardous waste if exhibits one of the four characteristics defined in 40 CFR Part 261 Subpart C - ignitability (D001), corrosivity (D002), reactivity (D003), and toxicity (D004 - D043).
1. Ignitability - Ignitable wastes can create fires under certain conditions, are spontaneously combustible, or have a flash point less than 60 °C (140 °F). Examples include waste oils and used solvents. For more details, see 40 CFR §261.21 . Test methods that may be used to determine ignitability include the Pensky-Martens Closed-Cup Method for Determining Ignitability (Method 1010A) (PDF) (1 pg, 19K) , the Setaflash Closed-Cup Method for Determining Ignitability (Method 1020B) (PDF) (1 pg, 17K) , and the Ignitability of Solids (Method 1030) (PDF) (13 pp, 116K) .
2. Corrosivity - Corrosive wastes are acids or bases (pH less than or equal to 2, or greater than or equal to 12.5) that are capable of corroding metal containers, such as storage tanks, drums, and barrels. Battery acid is an example. For more details, see 40 CFR §261.22 . The test method that may be used to determine corrosivity is the Corrosivity Towards Steel (Method 1110A) (PDF) (6 pp, 37K) .
3. Reactivity - Reactive wastes are unstable under "normal" conditions. They can cause explosions, toxic fumes, gases, or vapors when heated, compressed, or mixed with water. Examples include lithium-sulfur batteries and explosives. For more details, see 40 CFR §261.23 . There are currently no test methods available.
4. Toxicity - Toxic wastes are harmful or fatal when ingested or absorbed (e.g., containing mercury, lead, etc.). When toxic wastes are land disposed, contaminated liquid may leach from the waste and pollute ground water. Toxicity is defined through a laboratory procedure called the Toxicity Characteristic Leaching Procedure (TCLP) (Method 1311) (PDF) (35 pp, 288K) . The TCLP helps identify wastes likely to leach concentrations of contaminants that may be harmful to human health or the environment. For more details, see 40 CFR §261.24 .
Unless the UV/EB curing formulation is diluted with solvents, it typically does not meet the “ignitability” characteristic. UV/EB curing formulations also typically do not exhibit the EPA “corrosivity” criteria. UV/EB curing materials generally do not meet the “toxicity” characteristic, but formulations that contain toxic components, such as certain solvents or heavy metal pigments, may be identifiable as “toxic”.
Most UV/EB formulations do not meet the “reactivity” characteristic, but a few that comprise or contain mostly highly functional acrylates, such as PETA, DiPETA, DiTMPTA etc., have been known to react with the evolution of heat and fumes. These should be evaluated to determine whether they meet the “reactivity” criteria. If in doubt, they should be disposed of as potentially “reactive” wastes.
The waste generator has responsibility for determining if a waste is a RCRA hazardous waste. (See: 40 CFR 262.11). Four questions must be considered to determine whether the waste is hazardous:
1. Is the material a solid waste? (See: 40 CFR Part 261.2)2. Is the waste specifically excluded form RCRA? (See: 40 CFR Part 261.4)3. Is the waste a listed hazardous waste? (See: 40 CFR Part 261.30) 4. Does the waste exhibit a characteristic of hazardous waste? (See: 40 CFR Part 261.20)
If a UV/EB curing formulation, or UV/EB curing oligomers or monomers or photoinitiators, or clean-up wastes, or contaminated filters, wipes etc. meet any of these criteria, they must be disposed of in full compliance withy all applicable federal, state and local hazardous waste regulations.
If these wastes are not listed hazardous wastes or do not meet any of the hazardous waste characteristics, they may be disposed of as non-hazardous wastes in full compliance with all state and local regulations that apply to similar paints and coatings materials. This may require solidification or other treatment before disposal in a municipal land fill, so disposal as a hazardous waste may be a preferred alternative.
We are a printer of food contact packaging...
|We are a printer of food contact packaging. We read about the RadTech Food Contact Notification (FCN) Alliance. If we buy our inks in accordance and compliance with this new regulation would that be okay? What is necessary to be done? Do we need to become an Alliance member ourselves?
The raw material suppliers that are members of the FCN Alliance submitted to FDA extensive data on the composition, impurities and manufacturing processes of their products in order to have them cleared for use in food packaging under FCN 772. Raw materials from other suppliers have not been reviewed by FDA for safety in this way, and therefore can not qualify for use in food packaging under FCN 772, even if they nominally have the same composition. In order for formulations to be cleared under this FDA regulation, they must use only the raw materials purchased from the FCN member materials suppliers. If you can obtain certification that products comply with FCN 772 and all other FDA regulations that apply for the intended use, it would be cleared for use in food packaging in the USA.
I have heard about an issue with 4-MBP in Europe, can you tell me more?
|4-methylbenzophenone (MBP) was recently detected in a breakfast cereal in Europe, leading to publicity concerning this substance. RadTech has prepared a public statement, as well as background data and information for members concerning this issue. Please contact RadTech for more information.|
Are UV curing inks more or less flammable than conventional inks?
|In the uncured liquid state, UV and EB inks are no more flammable than conventional inks and may be less flammable because they contain little or no solvent, oils or rosin. Once they are applied and cured, the binders of UV and EB inks are highly cross-linked polymers similar to conventional inks based on based on polyester, urethane, acrylic and/or epoxy chemistry. In fact, since they normally do not contain residual oils or rosin, articles printed or coated with UV formulations should be less flammable than those produced with conventional inks and coatings. |
We are interested in applying UV curable coatings for concrete floors and other concrete surfaces, in some cases where there will be food preparation involved...
|We are interested in applying UV curable coatings for concrete floors and other concrete surfaces, in some cases where there will be food preparation involved. Are you aware of any designation or clearances that the coating must have before it can be used for these purposes? Do they require an FDA or USDA label or something similar?
The floor and walls of a food preparation or storage area normally are not expected to come into contact with food, so they are not required by regulation to be compliant with specific FDA citations in 21 CFR. This is not the case for food storage, handling and processing equipment. For example, a coating on the inside of a concrete food storage bin (grain bin or water tank, for example), on the other hand, must be FDA compliant, because contact is expected.
Food handling and processing equipment, such as food mixers and counter tops, may fall under the FDA “housewares” exemption, but any coating should be demonstrably safe for the intended application.
Under USDA guidelines, a guaranty is not required for coatings which do not meet the definition of packaging materials, even though there may be food contact. Though not covered under the packaging regulations, such materials may be regulated under other sections of the regulations. For example, performance and sanitation requirements for floors, walls, equipment and utensils are covered under Sections 308.5, 381.48 and 381.53 of the Meat and Poultry Inspection regulations.
Irrespective of regulatory compliance, if the customers demand FDA compliance even for floor coatings, that's their prerogative.
The good news is that it now is possible with FCN 772 to formulate an epoxy floor or concrete coating that specifically complies with FDA regulations, and it is foreseen that a limited amount of new test data on a urethane oligomer, for example, could allow an Alliance member to gain clearance for that type of oligomer and coating.