H1 lubricants for the food sector: what they are and when to use them
The machine goes in for maintenance, the operator grabs the lubricant at hand and greases the gears. If that machine works in a food zone, that gesture can be enough for a food non-conformity. Not because the lubricant is toxic, but because it didn't have the right registration. Understanding the H1 classification and when it applies saves you audit problems and, above all, real contamination risks.
The NSF classifications: H1, H2, H3
The NSF (National Sanitation Foundation) classification is the internationally recognized reference for lubricants in the food field.
The H1 category includes lubricants permitted for incidental contact with food: they are formulated with FDA-approved ingredients and you can use them where incidental contact between the lubricant and the food product is possible. The H2 category is for lubricants with no foreseen food contact, used in non-food zones of the machine. The H3 category covers water-soluble lubricants, such as edible oils, used for the temporary protection of surfaces.
For food machines, the operating rule is simple: always use H1 in any zone of the machine that isn't absolutely segregated from the production zone.
Reference regulations
Besides the NSF classification, H1 lubricants for the food sector must comply with:
- the EU Reg. 1935/2004, the European framework for materials in contact with food
- the FDA 21 CFR §178.3570 (Lubricants with Incidental Food Contact) for the American market
- the ISO 21469 standard (Hygiene Requirements for the Safety of Lubricants Used in the Manufacturing of Food, Feed, Pharmaceuticals and Cosmetics), for manufacturers who want to certify the lubricant production process
NSF H1 registration is the most practical way to demonstrate compliance and is recognized globally.
Lubricant bases and compatibility with technopolymers
| Lubricant base | Suitable for H1? | Compatibility with POM-C | Compatibility with PA6 | Notes |
|---|---|---|---|---|
| White mineral oil (paraffin) | Yes (classic H1 base) | Excellent | Excellent | Most economical base |
| PAO synthetic oil | Yes (H1 premium) | Excellent | Excellent | Better thermal stability |
| PEG synthetic oil | Yes (H1 formulations) | Good | Good | Hygroscopic, not for humid environments |
| Silicone grease | Yes (H1) | Excellent | Excellent | Excellent for high temperatures and humid environments |
| PTFE grease + H1 base | Yes | Excellent | Excellent | Very low friction, high durability |
| Vegetable oil (olive, soy) | H3 (edible) | Good | Good | Oxidizes rapidly, not for continuous use |
| MoS₂ or graphite lubricants | No (not H1) | Don't use in food | Don't use in food | Graphite and MoS₂ not permitted in food contact |
PAO stands for polyalphaolefins, a family of synthetic oils with high thermal stability and low volatility. PEG stands for polyethylene glycol: excellent surface wettability, but hygroscopic, that is, it absorbs moisture from the environment. In contexts with frequent washing or high humidity, evaluate alternatives.
Graphite and MoS₂ (molybdenum disulfide) are common additives in lubricants for industrial use, but they aren't permitted in food-contact zones. Always verify the complete composition of the lubricant, not just the classification on the packaging.
Dry running or H1 lubrication?
For technopolymer gears and components in food applications, in many cases dry running is preferable to H1 lubrication, precisely because it eliminates at the root the risk of contamination from lubricant. POM-C, PA6 and polyketone (PK) in dry running are food-grade materials: their wear doesn't produce problematic chemical contaminants.
H1 lubrication becomes necessary when the operating PV, that is, the product of contact pressure and peripheral speed, exceeds the limits of the material running dry, when the required service life is very high, or when the operating temperatures approach the material's limits.
In our experience, the first question to ask isn't "which H1 lubricant to use" but "can this component really run dry?". In many cases the answer is yes, and it simplifies both machine management and HACCP documentation.
Register of lubricants in the machine
The HACCP guidelines (Hazard Analysis and Critical Control Points, the system for analyzing and controlling food risks) and the ISO 22000 standard require documenting all the lubricants used in food-contact machines.
Keep a register of lubricants for each machine, with these minimum data:
- commercial name and manufacturer
- NSF H1 registration number
- application date
- quantity applied
- responsible operator
In case of an audit or food non-conformity, this register is the first documentation requested.
Don't confuse H1 with registered NSF H1
A lubricant "formulated with H1 ingredients" isn't equivalent to a lubricant with active NSF H1 registration. They're two different things.
Only products with a verifiable registration number on the NSF White Book (www.nsf.org) have valid certification. Using non-NSF-certified products in food-contact zones exposes you to legal liability in case of contamination, even if the manufacturer declares compliance.
Before using a lubricant in a food zone, look up the registration number on the NSF White Book. The manufacturer's declaration doesn't replace direct verification.
If you're configuring a food machine with technopolymer gears and have doubts about dry running or H1 lubrication under your operating conditions, contact the technical office: we assess the most suitable solution together.