GMP Surface Treatment

A partner in your compliance — not a one-time transaction.

Engineer-led derouging, passivation, and precision cleaning for pharmaceutical and biotech systems — on-site and in-house.

Why Catinox

We have been on your side of the table.

Surface treatment is usually sold as a job to get done. We approach it as an engineering challenge to understand. Our leadership specified, designed, and installed the same GMP systems we now service — so we already know what your quality team will ask for, because we used to ask for it.

What we're actually treating

Stainless steel protects itself with a thin, chromium-rich passive layer. When that layer breaks down, iron migrates to the surface and forms rouge. Removing the rouge is only half the work — restoring the passive layer is what prevents it from returning.

What we're actually treating Magnified schematic cross-section of a stainless-steel surface: an intact chromium-oxide passive layer, its breakdown into iron-oxide rouge, and the restored layer after treatment. Fe²⁺ / Fe³⁺ 1–5 nm · Cr₂O₃ 01 02 03 Stainless-steel substrate schematic · layers not to scale
01

Passive layer intact

Chromium-oxide film protects the steel

02

Passive layer breakdown

Iron migrates, rouge forms

03

Restored

Derouged and re-passivated

How we remove it — and rebuild what protects the steel

Derouging is a controlled, three-stage chemical process. We remove the iron-oxide corrosion, then restore the passive layer so the surface is protected again — not just visually clean.

How we remove it — and rebuild what protects the steel Schematic of one surface treated in three stages: iron oxides reduced to a soluble form, the dissolved iron bound and rinsed away, and the chromium-oxide passive layer rebuilt. Fe³⁺ → Fe²⁺ Fe²⁺ → [Fe·L] Cr₂O₃ 01 02 03 Stainless-steel substrate schematic · layers not to scale
01

Reduction

Insoluble iron oxides are converted to a soluble form.

02

Complexing

The dissolved iron is bound and rinsed from the surface.

03

Passivation

The chromium-oxide passive layer is rebuilt and protected.

What sets us apart
01 · Compliance

GMP compliance, managed as a plan

Not a one-off cleaning. We help establish your system's baseline, support a risk-based monitoring approach, and mobilize fast when rouge needs attention — so it stays a maintenance item, never an inspection finding. Backed by ISO 9001:2015 and validation-grade documentation.

02 · Expertise

Engineer-led — we know what we're treating

Our founders are pharmaceutical engineers who led CIP/SIP, water-for-injection, and clean-steam projects from business case through GMP start-up. That depth is the reason our compliance plans hold up to scrutiny.

03 · Root cause

Diagnose the cause, not just the symptom

Rouge returns unless the cause is addressed — water chemistry, chlorides, temperature, weld quality, lost passivation. We remove the rouge and help you understand why it formed, so the plan actually reduces recurrence.

Services

Two tracks. One standard.

On-site treatment for fixed pharmaceutical systems, and in-house treatment for components and small parts — delivered to the same GMP standard and documented the same way.

On-site

Derouging, passivation, and CIP cleaning performed in place. Your system never leaves your facility and never comes out of qualification.

In-house

Passivation, derouging, and ultrasonic cleaning for components and small parts — single-part jobs accepted, documented even at small scale.

Have a system that's rouging, or an inspection on the horizon?

Request a consultation