What Is Food-Grade Masterbatch, and What Documentation Should You Require?

The blow molding plant was supplying peach-colored HDPE bottles to a dairy beverage company. During the annual food safety audit, the auditor asked for the supporting documentation for the masterbatch, and the quality department handed over a compliance letter several years old, issued for a product family, with no product code, no conditions of use and no signature from a technical officer. The auditor rejected it and raised a nonconformity. When the file was reviewed, a second problem emerged: the supplier had changed one of the pigments in the shade months earlier, and the letter corresponded to the previous formula. The dairy company held the bottles from several weeks of production in its warehouse, its filling line ran with emergency white bottles and the blow molding plant was placed under review as a supplier.

Food-grade masterbatch contains pigments, carrier and additives permitted for food contact under defined conditions of use. Its support is a declaration of compliance by product code, with the regulation, use limits and date.

"Food grade": a commercial label that the audit translates into documents

The term "food grade" appears in data sheets and quotes, while regulations use other terms: materials intended to come into contact with food, permitted substances and conditions of use. A masterbatch complies for the uses its documentation covers, with the resin, let-down ratio, food type and temperature that the documentation specifies. Outside those conditions, the label loses its support, even if the formula is the same.

Three components under review: pigment, carrier and additives

Each component of the concentrate needs its own support. Under US FDA regulations, colorants for polymers are listed in 21 CFR 178.3297. The carrier, if it is a polyolefin, is governed by 21 CFR 177.1520, which covers olefin polymers. The antioxidants and stabilizers in the concentrate are listed in 21 CFR 178.2010. The waxes and dispersants that help disperse the pigment are also part of the formula. A serious declaration covers the complete concentrate.

Conditions of use: the limits that accompany each pigment

For several colorants, 21 CFR 178.3297 sets limits: a maximum percentage in the polymer, certain resin types or certain conditions of contact with food. That is why the same masterbatch can comply at a low let-down ratio in HDPE for a cold beverage and fall outside its scope at a higher let-down ratio, in another resin or in a hot fill. The let-down ratio programmed on your feeder is part of compliance.

What is at stake when the documentation arrives incomplete

The case of the peach bottles brings together the three most frequent gaps: a generic document, with no conditions of use and out of date with respect to the current formula. Each gap works through a different mechanism.

Migration: what is measured in the finished part

Migration is the transfer of substances from the plastic to the food. In the European Union, Regulation (EU) No 10/2011 sets an overall migration limit of 10 mg/dm² and specific migration limits for certain substances, which are verified with food simulants under defined time and temperature conditions. These tests are performed on the finished article, because migration depends on thickness, resin, food and use. The masterbatch documentation is the input that makes it possible to plan them; final verification is the responsibility of the converter and the brand. The color must not pass visibly into the food either, a phenomenon known as color migration.

Heavy metals and colorant purity

Some traditional inorganic pigments contain lead, cadmium or hexavalent chromium. In the United States, several state laws on toxic metals in packaging limit the combined content of lead, cadmium, mercury and hexavalent chromium. In the European Union, colorants fall outside the positive list of Regulation (EU) No 10/2011, and their purity is often evaluated with criteria such as Council of Europe Resolution AP(89)1. In Mexico, the health regulation of food contact packaging falls under the Ministry of Health, through Cofepris. A heavy metals declaration by product code answers all three reviews.

Good manufacturing practices: the condition behind the document

Every declaration assumes that the concentrate is manufactured under good manufacturing practices. The FDA establishes this in its general provisions in 21 CFR 174.5, and the European Union regulates it in Regulation (EC) No 2023/2006. In practice, this means controlled raw materials, equipment cleaning between one formulation and the next, and traceability for every lot. The same principle applies inside your plant. A machine that blows a bottle with a color that lacks food-contact support and then switches to a food container needs a complete purge. The regrind that returns to the hopper must come from production runs with the same support, because a remnant of another concentrate leaves the part outside what the letter declares.

Formula changes that make a current letter obsolete

A change of pigment, carrier or additive alters the basis of the declaration, even if the shade and the code remain the same. If the masterbatch supplier updates its formula without notice, the plant is left with a document that describes a product that has ceased to exist. That is why it is advisable to agree in writing that any formulation change be notified before the next shipment.

The file that should accompany a masterbatch for food contact

We recommend that your plant's quality department gather the following documents for each masterbatch code that comes into contact with food:

• Declaration of regulatory compliance by product code, with the regulation and sections cited, date of issue and signature of a technical officer.

• Conditions of use: permitted resins, maximum let-down ratio, food types and contact temperatures.

• For products exported to the European Union, a declaration of compliance under Regulation (EU) No 10/2011, with the substances subject to restrictions and the dual-use additives.

• Heavy metals declaration for the concentrate.

• Lot certificate of analysis, technical data sheet and safety data sheet.

• Written commitment to notify any formulation change.

With this file, the audit reviews one document per code and per current formula, and the plant responds in minutes.

How to read a compliance letter before accepting it

Scope: product, code and date

The letter must name the exact code of the masterbatch your plant buys. A letter for "the entire line" or for "our products" leaves the auditor with no way to link it to the bag that went into the hopper. The date of issue and the signature of a technical officer make it possible to confirm that it corresponds to the current formula.

Regulation cited and exact section

The phrase "complies with FDA" says little on its own. A useful letter cites the sections of the Code of Federal Regulations that apply to each component, such as 21 CFR 178.3297 for colorants and the section that corresponds to the carrier. If your product is exported to Europe, the reference should include Regulation (EU) No 10/2011 and the general framework of Regulation (EC) No 1935/2004.

Conditions of use compatible with your part

Compare the conditions in the letter with your actual product: the resin of the part, the let-down ratio you program, the food type and the filling or use temperature. An acidic, fatty or alcoholic food, a hot fill or a microwavable container requires conditions that the letter must cover explicitly.

The support behind our food-contact masterbatch at Delta Pigmentos

At Delta Pigmentos we have been manufacturing masterbatch in our own plant for 24 years. Our Basic Color Line, for HDPE, LDPE and PP, includes options recommended for food contact under FDA 21 CFR 178.3297, identified in the catalog with the FDA mark, such as MB-Blanco DP-4536A, MB-Azul DP-3158A and MB-Negro LGA-1023A. Our PE White Masterbatch reaches up to 70% pigment concentration and is free of heavy metals.

When the shade is a brand color, we match it to order, and it is advisable to state the end use from the quote stage so that our Quality Control, Design and Development laboratory selects pigments permitted for that application. When requesting a quote, tell us the resin, the process, the food type, the use temperature, the destination market and the documents your customer requires. We produce under ISO 9001-2015 certified procedures and ship anywhere in the country from Santa Anita, Jalisco.

Frequently asked questions

Is an FDA letter for the masterbatch enough to export to the European Union?

The European Union applies its own framework: Regulation (EC) No 1935/2004, Regulation (EU) No 10/2011 with its declaration of compliance, and migration testing on the finished article. To export, ask your supplier for the European declaration of compliance in addition to the FDA letter.

How often should the declaration of compliance be updated?

Every time the masterbatch formula or the cited regulation changes. In addition, it is advisable to request a recently dated letter before each audit and to verify that the code and formula match what your plant buys.

Can food-grade masterbatch be used for any food and temperature?

It can be used under the conditions its documentation covers. An acidic or fatty food, a hot fill or microwave use may fall outside those conditions. State the end use when requesting a quote to receive the option and the documentation that correspond to your application.

Food-grade masterbatch is supported by documents by code, by current formula and by conditions of use, and that file protects your plant in every audit. At Delta Pigmentos we manufacture masterbatch with options recommended for food contact under FDA 21 CFR 178.3297, with our own laboratory and ISO 9001-2015 certified procedures. Write to us on WhatsApp from https://deltapigmentos.com with your resin, your process, the food the part will contain and the documentation your customer requires; we will respond with a technical proposal. Every request is reviewed within the following 24 business hours.