Download PDF

LCA results & interpretation Conventional Loose-Fill Cellulose Insulation

Scope and summary

  • Cradle to gate
  • Cradle to gate with options
  • Cradle to grave


Conventional loose-fill cellulose insulation is made from any cellular plant source although it typically comes from waste paper products. It is installed by using an insulation blowing machine. Conventional loose-fill cellulose insulation is typically applied to enclosed areas, unfinished attic floors, and other hard to reach places.

Functional unit

Reference service life: 75 years. One square meter of installed insulation material, packaging included, with a thickness that gives an average thermal resistance of RSI=1m2·K/W over a period of 75 years. ASTM C518 was used to determine R-value.

Reference flow range: 0.8352-1.181 kg

Thickness range: .038-.043 m

Density range: 20.27-28.35 kg/m3

Manufacturing data

Reporting period: January--December, 2018

Representing 13 locations across the United States and Canada 

(Ohio, Arizona, Colorado, Kentucky, Georgia, Louisiana, Wisconsin, Pennsylvania, Alabama, New York, Alaska, Missouri, Texas, Iowa, Michigan, Alberta, Quebec, Ontario) Conventional loose-fill cellulose insulation is produced in several manufacturing steps that involve the blending of fibers, adding the fire retardant in liquid form to the fibers, and then drying and milling the fibers before placing them into bags.  


All submitted data were checked for quality multiple times on the plausibility of inputs and outputs. All questions regarding data were resolved with CIMA manufacturers. 

Default installation, packaging, and disposal scenarios

At the installation site, insulation products are unpackaged and installed with a blowing machine. The potential impact of the blower is included in this study. Plastic packaging waste is disposed (100% to landfill), and no maintenance or replacement is required to achieve the product's life span. After removal, the insulation is assumed to be landfilled.

Uncertainty analysis of industry-wide results

An uncertainty analysis is done to measure how the LCA results of each product differ due to the differences in the data inputs and determine if each product falls within the industry average mean. A Monte Carlo uncertainty analysis was done in SimaPro for each participant. The results were converted from yearly outputs to the functional unit and averaged for all the companies, which provides the uncertainty range for the impact categories used for comparison. The average is representative of data from all 13 manufacturers. This range is the confidence interval. A 95% confidence level demonstrates the confidence that the results are representative of all cellulose insulation manufacturers, based on this sample.

This industry-wide EPD serves as a product group benchmark to which product-specific results can be compared. Three impact categories are used for comparison. The PCR requires global warming and the other two were selected because they had the lowest variability (see table to the left). When a manufacturer compares its product-specific results, if the environmental impact is within the range, it is determined to be equivalent to the industry impact; below the range, lower impact; above the range, higher impact.

The Embodied Carbon in Construction Calculator (EC3) from the Carbon Leadership Forum and industry partners is designed to enable the building industry to transparently measure, compare, and reduce embodied carbon emissions from construction materials. See how the embodied carbon in cellulose insulation compares to other types of insulation products. 

What’s causing the greatest impacts

All life cycle stages

For the loose-fill cellulose insulation product, the raw materials acquisition, transportation to the manufacturing site, and manufacturing stages (A1-A3) dominate the results for all impact categories. This study assessed a multitude of inventory and environmental indicators. The overall results are consistent with expectations for insulation products’ life cycles, as these products are not associated with energy consumption during their use stage. LCIA results are relative expressions and do not predict impacts on category endpoints, the exceeding of thresholds, safety margins or risks. These six impact categories are globally deemed mature enough to be included in Type III environmental declarations; other categories are being developed and defined and LCA should continue making advances in their development, however the EPD users shall not use additional measures for comparative purposes. For an average EPD for a declared unit of R-value of a specific type of insulation material, the representativeness of the average EPD could be described by relevant technical properties such as the range of density, thermal conductivity and thickness for which the average EPD is representative.

The primary finding, across the environmental indicators, was that raw material acquisition, transportation to manufacturing facility, and the manufacturing stages (A1-A3) dominate the impacts due mainly to the raw materials. Chemicals such as boric acid and ammonium, used as fire retardants, have a lower ecotoxicity. Transportation (A1) of raw materials to manufacturing contribute mainly to fossil fuel depletion and global warming due to emissions of trucks and trailers. Transportation of the final products to distribution facilities (A4) is the second highest contributor for these impact categories. 

Installation accounts for a small fraction of overall life cycle impact. The only installation impacts are associated with packaging disposal and the gas and electricity used for an installation blower machine. There is no impact associated with the use stage. While insulation can influence building energy performance, this aspect is assumed to be outside the scope of this study. Additionally, it is assumed that insulation does not require any maintenance to achieve its reference service life, which is modeled as being equal to that of the building. No replacements are necessary; therefore, results represent the production of one square meter of insulation at a thickness defined by the functional unit.

At the end of life, insulation is removed from the building and land-filled. For all products, waste was dominated by the final disposal of the product. Non-hazardous waste also accounts for waste generated during manufacturing and installation. Non-hazardous waste is associated with product end-of-life when it is disposed to a landfill so no reporting of this done for A3. No substances required to be reported as hazardous are associated with the production of this product. 

The results show that the largest area for reduction of each product's environmental impact is in the raw material acquisition and manufacturing phase. This can be done by turning of certain machines when they are not in use and recycling dust emissions back into their product to reduce manufacturing impacts.

Raw materials acquisition stage

The impact of the raw material acquisition stage is mostly due to chemicals such as boric acid and ammonium sulfate. This is because of the high material weights used in manufacturing. 

Multi-product weighted average

For an average EPD for a declared unit of R-value of a specific type of insulation material, the representativeness of the average EPD could be described by relevant technical properties such as the range of density, thermal conductivity and thickness for which the average EPD is representative.Results represent the weighted average using production volumes for the products covered. Variations of specific products in grid mix, manufacturing techniques, raw material composition, and different supply chains account for differences of 10–20% against the average are indicated in purple; differences greater than 20% are indicated in red. A difference greater than 10% is considered significant.    

Cellulose insulation has very low embodied carbon due to the use of recycled raw material content, low embodied energy during manufacturing, and sequesters carbon.

It is an inherently recycled product with 85%, or more, recovered content, most of which is post-consumer.  A medium size cellulose insulation plant will convert three to five truckloads, or more, of recovered paper to energy-saving insulation each production shift.

The energy used to make cellulose insulation is referred to as embodied energy. It includes the energy required to transport raw materials, manufacture and distribute the product. Using mostly locally sourced materials manufactured in electrically-driven mills, which can be shut down between production runs and do not need to run 24x7, cellulose insulation is an extremely energy efficient product to produce.

Since the primary feedstock -- recovered paper fibers -- is derived from trees, cellulose insulation sequesters carbon in the walls and ceilings of homes for the life of the building. 

See how we make it greener

LCA results

Life cycle stage Raw material acquisition and manufacturing Transportation Installation and maintenance Transportation Disposal/reuse/ recycling

Information modules: Included | Stages C1, C3, and D are excluded.

In the installation and maintenance phase, packaging waste and electricity or gas used by the insulation blowing machines in module A5 are the only contributors to the potential impacts.

A1 Raw Materials A4 Transporation/ Delivery A5 Construction/ Installation C2 Transportation C4 Disposal
A2 Transportation   B1 Use    
A3 Manufacturing   B2 Maintenance    
    B3 Repair    
    B4 Replacement    
    B5 Refurbishment    
    B6 Operational energy use    
    B7 Operational water use    
Impacts per 75 years of service 4.03E-05 mPts 8.49E-06 mPts 1.83E-07 mPts 2.48E-06 mPts 7.39E-07 mPts
Materials or processes contributing >20% to total impacts in each life cycle stage Boric acid and ammonium sulfate used in the production of the insulation. Truck and trailor, rail, and ship transportation used to transport product to manufacturing site. Transportation to disposal, energy required for installation with a blowing machine, and disposing of packaging materials. Transportation to landfill. Landfilling of product.

TRACI v2.1 results per functional unit

  • A variation of 10 to 20%
  • |
  • A variation greater than 20%
Life cycle stage Raw material acquisition and Manufacturing Transportation Installation and maintenance Transportation Disposal/reuse/ recycling

Ecological damage

Impact category Unit
Acidification kg SO2 eq Kilograms of Sulfur Dioxide equivalent
Acidification processes increase the acidity of water and soil systems and causes damage to lakes, streams, rivers and various plants and animals as well as building materials, paints and other human-built structures.
3.26E-03 3.36E-04 1.89E-05 9.80E-05 6.72E-05
Eutrophication kg N eqKilograms of Nitrogen equivalent
Eutrophication is the enrichment of an aquatic ecosystem with nutrients (nitrates and phosphates) that accelerate biological productivity (growth of algae and weeds) and an undesirable accumulation of algal biomass which impacts industry, agriculture, drinking, fishing and recreation and causes death of fish and shellfish, toxicity to humans, marine mammals and livestock, and reduces biodiversity.
4.22E-04 4.79E-05 1.21E-06 1.40E-05 7.75E-06
Global warming (Embodied carbon) kg CO2 eqKilograms of Carbon Dioxide equivalent
Global warming is an average increase in the temperature of the atmosphere near the Earth’s surface and in the troposphere, which can contribute to change in global climate patterns and is caused by the increase of the sources of greenhouse gases and decrease of the sinks due to deforestation and land use. GW leads to problems in human health, agriculture, forest, water source and damage to species and biodiversity as well as coastal areas.
4.87E-01 8.99E-02 1.70E-03 2.62E-02 8.47E-03
Ozone depletion kg CFC-11 eq Kilograms of Trichlorofluoromethane equivalent
Ozone depletion is the reduction of ozone in the stratosphere caused by the release of ozone depleting chemicals. Ozone depletion can increases ultraviolet B radiation to the earth which can adversely affect human health (skin cancer and cataracts and immune-system suppression) and other system (marine life, agricultural crops, and other vegetation) and causes damage to human-built materials.
7.20E-08 2.17E-08 7.97E-11 6.34E-09 3.06E-09


LCA Background Report

CIMA and CIMAC Loose-Fill Cellulose Insulation Products LCA Background Report (public version), CIMA and CIMAC 2019. SimaPro Analyst, ecoinvent 3.1, 2.2 database.


ISO 21930:2017 serves as the core PCR along with EN 15804 and UL Part A.

ULE PCR Part A: Life Cycle Assessment Calculation Rules and Report Requirements v3.1

May 2, 2018. Technical Advisory Panel members reviewed and provided feedback on content written by UL Environment and USGBC. Past and present members of the Technical Advisory Panel are listed in the PCR.

ULE PCR Part B: Building Envelope Thermal Insulation

Version 2.0, April 2018. PCR review conducted by Thomas Gloria, PhD (chair, [email protected]; Andre Desjarlais; and Christoph Koffler, PhD.

ISO 14025, “Sustainability in buildings and civil engineering works -- Core rules for environmental product declarations of construction products and services”, ISO21930:2017

blue-2pdf.png#asset:15427  Download PDF SM Transparency Report, which includes the additional EPD content required by the UL Environment PCR.

SM Transparency Reports (TR) are ISO 14025 Type III environmental declarations (EPD) that enable purchasers and users to compare the potential environmental performance of products on a life cycle basis. They are designed to present information transparently to make the limitations of comparability more understandable. A limitation to this study is that not all manufacturers in North America participated. TRs/EPDs of products that conform to the same PCR and include the same life cycle stages, but are made by different manufacturers, may not sufficiently align to support direct comparisons. They therefore, cannot be used as comparative assertions unless the conditions defined in ISO 14025 Section 6.7.2. ‘Requirements for Comparability’ are satisfied. Comparison of the environmental performance of building envelope thermal insulation using EPD information shall be based on the product’s use and impacts at the building level, and therefore EPDs may not be used for comparability purposes when not considering the building energy use phase as instructed under the PCR. Full conformance with the PCR for building envelope thermal insulation allows EPD comparability only when all stages of a life cycle have been considered, when they comply with all referenced standards, use the same sub-category PCR, and use equivalent scenarios with respect to construction works. However, variations and deviations are possible. Example of variations: Different LCA software and background LCI data sets may lead to different results upstream or downstream of the life cycle stages declared.

Rating systems

The intent is to reward project teams for selecting products from manufacturers who have verified improved life-cycle environmental performance.

LEED BD+C: New Construction | v4 - LEED v4

Building product disclosure and optimization 

Environmental product declarations

  • Industry-wide (generic) EPD ½ product

  • Product-specific Type III EPD 1 product

LEED BD+C: New Construction | v4.1 - LEED v4.1

Building product disclosure and optimization 

Environmental product declarations

  • Industry-wide (generic) EPD 1 product

  • Product-specific Type III EPD 1.5 product

Green Globes for New Construction and Sustainable Interiors

Materials and resources

  • NC Path B: Prescriptive Path for Building Core and Shell

  • C and SI 4.1.2 Path B: Prescriptive Path for Interior Fit-outs

Collaborative for High Performance Schools National Criteria

MW 7.1 – Environmental Product Declarations

  • Third-party certified type III EPD 2 points

BREEAM New Construction 2018

Mat 02 - Environmental impacts from construction products

Environmental Product Declarations (EPD)

  • Industry average EPD .5 points

  • Multi-product specific EPD .75 points

  • Product specific EPD 1 point