Passive Fire Protection

ISO 12944 (Passive Fire Protection)

Protective coatings for passive fire protection ISO 12944 and BS 476 Parts: 20/21, BS 476: Parts 6/7 Class O, EN13823 (SBI) and IMO smoke / toxicity systems

The ISO 12944 standard is designed as a guideline for Architects, Engineers, Specifiers, Contractors and Applicators in formulating corrosion protection systems.

This guide is intended as a basic introduction to ISO 12944 and BS 476 with a choice of approved Complete Coating Services Specifications.


Three easy steps to follow

1. Select Environment

2. Select Durability

3. Select System

1. Select Environment

Corrosion Environment
(ISO 12944-2 : 5.1.1)

C1 Very LowHeated buildings with clean atmosphere, e.g. offices, shops, schools and hotels.
C2 LowAtmospheres with low level of pollution.
Mostly rural areas.
Unheated buildings where condensation may occur, e.g. depots and sports halls.
C3 MediumUrban and industrial atmosphere, moderate sulphur dioxide pollution. Coastal areas with low salinity.Production rooms with high humidity and some air pollution, e.g. food processing plants, laundries, breweries and diaries.
C4 HighIndustrial areas and coastal areas with moderate salinity.Chemical plants, swimming pools, coastal ships and boat yards.

2. Select Durability

Durability (ISO 12944-1: 4.4)Years to 1st major maintenance
Low (L)2 - 5 years
Medium (M)5 - 15 years

Durability consideration

How long do you want the system to last before any major maintenance?

Is the steelwork readily accessible for maintenance?

3. Select a Complete Coating Services System

C1 Very Low
C2 Low
C3 Medium
C4 High

System Selector Life Expectancy (Exposure conditionals are defined in ISO 12944)

Exposure Conditions
(ISO 12944)

DescriptionDry internal controlledInternal / dry semi controlled no condensationInternal / damp semi controlledInternal uncontrolled frequently wet
Typical EnvironmentHeated buildings e.g. clean atmosphereUnheated buildings e.g. depots & sports halls etc.Higher Humidity situations e.g. carparksChemical Plants swimming pools
Use (Note 1)Steelmaster 60/120 or 60WB
Steelmaster 60/120 or 60WB
Steelmaster 60/120 or 60WB
Steelmaster 60/120
Pioner Topcoat DFT* TOP sealer for 30/120 (Microns)505075 – 100100
Typical primerAlkyd PrimerAlkyd PrimerTwo Pack Zinc Phosphate EpoxyTwo Pack Zinc Rich Epoxy

Note 1: please consult if protection is for more than 60 minutes.