Delrin FDA Food-Grade — Delrin 150SA & 500SA Compliance

Delrin 150SA and 500SA are DuPont's designated FDA-compliant acetal homopolymer grades, meeting the requirements of 21 CFR 177.2480 (Acetal resins — repeated use food-contact). These grades use only FDA-listed polymerization catalysts, stabilizers, and colorants — no additives outside the CFR permitted list. For engineers specifying food-contact plastic components in machined or molded parts, the "SA" designation is the trigger for compliance traceability. This page covers the regulatory scope, grade differences, hot-water limitations, NSF certification status, and documentation requirements.

At a glance:

• Delrin 150SA and 500SA: primary FDA food-contact grades
• Regulation: 21 CFR 177.2480 — Acetal copolymers (note: same regulation covers both POM-H and POM-C)
• Hot-water limitation: Delrin (POM-H) is not recommended for continuous service above 140°F (60°C) in food-contact; use acetal copolymer for hotter applications
• Color: natural (white/ivory) only — black and pigmented Delrin is typically not FDA-compliant
• NSF 51 (food equipment): select Delrin SA grades carry NSF 51 listing
• Documentation: request certificate of conformance citing grade, lot number, and 21 CFR 177.2480 with each shipment

FDA 21 CFR 177.2480: What It Covers

Title 21 of the Code of Federal Regulations, Part 177.2480 is the FDA regulation governing polyacetal resins (both homopolymer POM-H and copolymer POM-C) intended for repeated-use food-contact applications. The regulation:

• Lists permitted monomers (formaldehyde; for copolymers, trioxane plus permitted comonomers)
• Lists permitted adjuvant substances (stabilizers, antioxidants, lubricants — each must appear on the permitted list)
• Specifies extraction limits for total extractables in food simulants
• Covers "repeated-use" contact, meaning articles designed for continued use rather than single-use disposables

The key implication: not every Delrin grade is compliant. Only grades that use exclusively CFR 177.2480-listed adjuvants qualify. Colored grades and grades containing non-CFR-listed processing aids do not automatically qualify.

Delrin 150SA — FDA-Compliant Extrusion Grade

Delrin 150SA is the FDA-compliant version of Delrin 150 — the medium-high molecular weight grade optimized for extrusion into rod, sheet, and tube stock shapes. The "SA" suffix (historically from "sans additifs" in DuPont's French-heritage designation) confirms the grade uses only FDA-listed additives.

Properties of Delrin 150SA

Properties are essentially identical to standard Delrin 150:

Typical Applications of Delrin 150SA

• Food processing equipment: conveyor guides, wear strips, cams, and chain sprockets
• Cutting boards and food-contact guides in meat, produce, and bakery processing
• Dairy and beverage equipment: valve seats, cam followers, and pump components
• Vending machine dispensing mechanisms in direct product contact
• Packaging machinery: seal bars, film guides, and indexing cams

Delrin 500SA — FDA-Compliant General-Purpose Grade

Delrin 500SA is the FDA-compliant analog of Delrin 500, the standard injection molding grade. It provides the same balanced properties as Delrin 500 — good tensile strength, moderate toughness, excellent machinability — with FDA-listed additive package.

Delrin 500SA is the preferred grade when:

• Parts are injection-molded from pellets rather than machined from stock (500-series grades are the injection molding standard)
• General-purpose food-contact machined parts are needed and 150SA stock is unavailable in the required size
• Cost optimization favors 500SA over 150SA (usually negligible difference)

Hot-Water Limitation for Delrin in Food Contact

This is the most important compliance engineering consideration for Delrin (POM-H) in food applications:

Temperature Guidance for Delrin in Food Contact

NSF Certification

NSF International certifies food-equipment and drinking-water materials independently of FDA. Two relevant NSF standards:

NSF/ANSI 51 — Food Equipment Materials: Covers plastics in direct and indirect food contact in commercial food service. Delrin SA grades carry NSF 51 listings in many standard product forms. Verify current NSF listing at the NSF Product and Service Listings database for the specific grade and form.

NSF/ANSI 61 — Drinking Water System Components: Covers plastics in drinking water contact. Applicable to Delrin components in water meters, pipe fittings, and valve bodies used in potable water systems. Selected Delrin grades carry NSF 61 certification; verify by lot number.

USDA Acceptance

The USDA's Food Safety and Inspection Service (FSIS) regulates materials used in meat and poultry processing equipment. USDA-accepted plastics must meet FDA requirements and additional USDA Guidelines for Food Contact Surfaces. Delrin SA grades are accepted by USDA for use in federally inspected meat and poultry processing plants when used appropriately (not above the recommended service temperature, not in continuous hot-water contact).

EU and International Food-Contact Compliance

For parts intended for European markets:

EU Regulation 10/2011 (Plastic Materials in Food Contact): Acetal (POM) is covered under Union List substances. Delrin SA grades from a European-supply chain (Ticona/Celanese) may carry a Declaration of Compliance (DoC) under EU 10/2011. Request the DoC from the distributor.

BfR (German Federal Institute for Risk Assessment): BfR recommendations for polyoxymethylene (BfR VIII Recommendation) are the German national supplement; Delrin SA grades generally comply. Request supplier BfR documentation for EU-regulated applications.

Documentation Requirements

When procuring FDA-grade Delrin for food-contact applications, request:

1. Certificate of Conformance (CoC): States the grade designation (Delrin 150SA or 500SA), lot number, and confirmation of compliance with 21 CFR 177.2480
2. FDA compliance letter: DuPont/manufacturer's letter confirming the grade's CFR 177.2480 status (one-time reference document; re-verify if grade or supplier changes)
3. NSF listing documentation (if required): Current NSF product listing printout for the specific grade

Write your purchase orders to require: "Delrin 150SA [or 500SA], ASTM D6100 Type I, with FDA 21 CFR 177.2480 certificate of conformance."

Comparing Delrin SA to Acetal Copolymer FDA Grades

For food applications involving hot water or large rod diameters, evaluate acetal copolymer FDA grades before defaulting to Delrin SA.

More related guides

Compliance and regulatory

• Acetal Copolymer FDA Food-Grade
• PEEK FDA and USP Class VI Compliance

Industries

• Food Processing Plastics

Frequently asked questions — Delrin FAQ