Link points to Internet Archive / others. Not hosted by InfraLens. Details
IS 9789:1981 is the Indian Standard (BIS) for rigid cellular phenolic foam for thermal insulation. This specification outlines the requirements and test methods for rigid cellular phenolic foam intended for thermal insulation applications. It covers essential physical properties such as density, thermal conductivity, compressive strength, water absorption, and flammability to ensure material quality and performance.
Specifies requirements for rigid cellular phenolic foam used for thermal insulation.
! Phenolic foam is known for its excellent fire resistance properties but can be more brittle than other foam insulations; handle with care during installation.
! Verify the compatibility of adhesives, sealants, and facing materials, as certain solvents can chemically attack and degrade the foam.
! The standard has been superseded by IS 12436, which should be referred to for new projects, though IS 9789 may be cited in older project specifications.
Provides a framework and general requirements for rigid cellular plastics, including phenolic foam, but is not material-specific.
BS 3927:1986BSI (British Standards Institution), UK
HighWithdrawn
Specification for rigid phenolic foam (PF) for thermal insulation in the form of slabs and sections
Specified requirements for rigid phenolic foam slabs and sections, serving as the precursor to the EN standard in the UK.
Key Differences
≠The IS code defines a single type of product, whereas modern standards like EN 13166 and ASTM C1126 use a classification system (e.g., Types in ASTM based on density/facing; designation codes in EN based on performance levels for various properties).
≠Fire performance testing in IS 9789 is based on older Indian methods (e.g., reference to IS 3144), which are less comprehensive than the current Euroclass system (EN 13501-1) required by EN 13166 or the ASTM E84 flame spread/smoke developed tests in ASTM C1126.
≠EN 13166 specifies a 'declared thermal conductivity' (λD) based on a 90/90 statistical evaluation and includes ageing, providing a long-term performance value. IS 9789 specifies a simple maximum initial value at a specific mean temperature.
≠Modern standards provide multiple levels for properties like dimensional stability and compressive strength (e.g., CS(10\Y)100, CS(10\Y)125 in EN 13166), allowing manufacturers to declare performance. The IS code provides a single minimum or maximum value.
Key Similarities
≈All standards are fundamentally focused on specifying the material requirements for rigid cellular phenolic foam intended for use as thermal insulation.
≈Core physical properties such as thermal conductivity, compressive strength, density, and water absorption are specified in all standards, forming the basis for quality assessment.
≈All standards specify requirements for the material in the form of boards or slabs, which is the primary product format for this type of insulation.
≈There is a common requirement for high closed-cell content (typically ≥90%) to ensure good thermal performance and low moisture absorption.
Parameter Comparison
Parameter
IS Value
International
Source
Apparent Density
35-45 kg/m³ (Nominal, as agreed between purchaser and supplier) with ±10% tolerance.
Type II: 2.2 lb/ft³ (35 kg/m³); Type IV: 3.5 lb/ft³ (56 kg/m³)
ASTM C1126-22
Compressive Strength (at 10% deformation)
≥ 1.2 kgf/cm² (120 kPa)
≥ 20 psi (138 kPa) for Type II
ASTM C1126-22
Thermal Conductivity (max value)
≤ 0.023 W/(m·K) at 10°C mean temperature
≤ 0.023 W/(m·K) [0.16 Btu·in/h·ft²·°F] at 24°C (75°F) mean temp for thickness < 1 inch
ASTM C1126-22
Closed Cell Content
≥ 90%
≥ 90%
ASTM C1126-22
Water Absorption (by volume, full immersion)
≤ 5% after 7 days
≤ 4% after 96 hours
ASTM C1126-22
Dimensional Stability (Linear Change, %)
≤ 2% after 7 days at 70°C & 95% RH
≤ 2% after 7 days at 70°C & 97±3% RH (DS(TH) level)
EN 13166:2012+A2:2016
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Maximum Thermal Conductivity (at 10°C mean temp)0.040 W/m.K
What is the maximum thermal conductivity allowed by this standard?+
The maximum thermal conductivity is 0.040 W/m.K when tested at a mean temperature of 10°C, as per Table 1.
What is the minimum required compressive strength?+
The minimum compressive strength at 10 percent deformation is 100 kPa (or 1.0 kgf/cm²), according to Table 1.
What are the fire performance requirements?+
The material must have a maximum rate of burning of 150 mm/min when tested as per the method in Appendix A-11.
Does this standard specify the density?+
No, it does not specify a mandatory density. It requires the 'Apparent Density' to be declared by the manufacturer and to be within ±10% of the declared value (Table 1).