Building Materials Certification and Healthy Indoor Air

Building Materials Certification and Healthy Indoor Air

It is a common statistic when talking about the quality of indoor air, that we spend approximately 90% of our time indoors. The origin of that statistic was a study by the US Environmental Protection Agency back in 19891. The importance of this is the nature of the contained environment of the home; in the move towards greater environmental sustainability, homes have become more energy efficient and more tightly sealed. While this provides a better environmental impact, it also means that the air in the home does not become renewed through passage of fresh air.

This increased amount of time indoors means that the indoor environment, and its impact on overall health, is more important than ever. The life cycle of a building, in the context of its use is divided into:

  • Design
  • Construction
  • Usedesign, construction, use

At all stages in the cycle, the health of the subsequent inhabitants can be considered, and nowhere is this more important than in design. Buildings that are poorly designed are those that are most likely to cause ill-health of its occupants, and particularly those suffering from asthma and allergies.

Flat roofs in heavy rain areas, limited or no natural sunlight, poorly designed HVAC systems, improper material selection are all elements that can be addressed easily at design stage, but can be very costly or impossible to remediate once the building is complete. During construction, the type of material used can impact on the subsequent health of the occupant. Finally, during use and fit-out of the building, different approaches can be taken to make the indoor environment a more comfortable and healthy one.

Certification Programs

The Leadership in Energy and Environmental Design (LEED) is the longest running program that addresses a range of building material related issues. LEED was first launched in 1998 by the US Green Building Council and gained significant traction around the world since then. The purpose of LEED is to provide a central resource to identify materials that are more suitable for use in green buildings. A central driver of LEED has been its adoption by Government Agencies with procurement preference given for materials and companies that are LEED certified.

Since this time, a range of certification standards and programs have been developed with the aim of providing a healthier and more comfortable indoor environment; however, a green building is not necessarily more healthy. The WELL Home Institute is the most comprehensive certification standard, taking into account a range of attributes of a building. LEED is the next widest ranging program, followed by Cradle 2 Cradle, Declare and Environmental Product Declaration. The remaining Certification Programs outlined below focus specifically on materials in terms of their impact on indoor air quality. The main difference within these programs is that the asthma & allergy friendly® Certification Program is the only one to focus on this cohort and to consider biological contaminants, in addition to chemical ones.

The impact of the indoor environment is particularly important for those suffering from asthma and allergies. The length of time spent indoors, and the potential trigger compounds that exist here are significant risk factors for this group of people; but how many building certifications take this into consideration?


Building materials certification ecosystem and overview.Building materials certification ecosystem and overview.











Figure 1. Building materials certification ecosystem and overview.


  1. International WELL Building  Institute (IWBI):

The WELL Building Standard is the most comprehensive standard in terms of the entire life  cycle and function of a building. Their standard is divided into 10 sections.

The most relevant sections for those suffering from asthma and allergies are air, thermal comfort and materials. Good quality indoor air is essential for those suffering from asthma and allergies, and this standard does address this, however while monitoring of indoor and outdoor air is recommended, the focus of this is on the general population, rather than those who may be more sensitive to airway irritants. Thermal comfort is relevant in terms of ensuring a relative humidity less than 50% so that dust mites and fungi will not grow, however this standard allows up to 60% humidity, which will allow dust mites to grow. Material composition and function is addressed in this standard and is summarised in Table 1, however the impact of biological elements is not addressed, ie removal of pollen and other allergens .

  1.  Air

    Air is clearly a fundamental of indoor health. Poor indoor air quality can lead to poor health. The IWBI address this important element through a range of sections, all of which can contribute to a building becoming certified. Indoor air must be of a basic quality, this is a platform requirement that the subsequent requirements are built on. Other measures include:

    • Deterring smoking and exposure to second hand smoke
    • Sufficient and enhanced ventilation, with measurement
    • Mitigation during construction activities
    • Operable windows in areas of good outdoor air quality
    • Air quality monitoring and awareness – indoor and outdoor
    • Maintaining HVAC filter efficacy
    • Microbe and mold control through condensation management and effective cleaning
  2. Water

    This section of the standard covers all aspects of water including quality, distribution and control. Legislation defines minimum quality of drinking water and this defines the thresholds used in this section related to sediment, micro-organisms and also heavy metals, organic pollutants, disinfectant by-products, pesticides and fertilizers. Similarly to air quality, while basic water quality is addressed, enhanced water quality is also encouraged with higher thresholds defined for water to achieve.

    • Water quality consistency
    • Promotion of drinking water and staying hydrated
    • Moisture control
    • Encouraging regular hand washing
    • Treatment of non-potable water for discharge
    • Encouragement of healthy diets – fruit and vegetables; avoiding refined and artificial ingredients
    • Mindful eating and nutrition education
  3. Lighting

    Lighting is recognised as being important within this standard in terms of visual, mental and biological health. The first part of this section addresses education on how light affects inhabitants and also defines basic lighting requirements and design. Additional requirements are:

    • Reduction of glare from workstations and poor quality lighting
    • Daylight is preferred where possible, compared to artificial light
    • Access to daylight
    • Encouragement of environments that enhance visual comfort
    • Customizable lighting environments
  4. Movement

    Movement, physical activity and active living are encouraged within the IWBI standard, facilitated through the design of built spaces. Ergonomic design is a precondition and physical daily activities and movement are recommended to be facilitated through the design of the building. Other requirements are:

    • Facilities should be provided that will encourage active lives
    • Proximity to mass transit
    • Active workstations should be provided to reduce sedentary activity
    • Provision of physical activity equipment
    • Enhanced ergonomic design
    • Incentives to take up physical activity and helping individuals to self-monitor their activity levels.
  5. Thermal Comfort

    Thermal comfort is an essential part of productivity, however it can be quite subjective. A prerequisite in this section is that the majority of users find the thermal environment acceptable. Other requirements include:

    • Substantial majority perceive their thermal environment as acceptable.
    • Effective HVAC system
    • Design of thermal zoning and provision of individual thermal comfort devices
    • Monitoring of the thermal comfort levels within the building
    • Control of relative humidity.                            
  6. Sound

    Acoustic comfort is also addressed within this standard; sound mapping is a prerequisite, together with mitigation to understand the acoustic environment of the building. In addition:

    • Maximum sound levels are defined
    • Provision of sound barriers
    • Design of space to absorb sound and provision of sound masking
    • Floors should also be designed to reduce noise from foot impact.
  7. Materials

    Materials are a fundamental part of building design, and should be considered in terms of their impact on the indoor environment. A prerequisite of this standard is the reduction or elimination of materials known to be hazardous. Requirements include:

      • No asbestos, mercury or lead are addressed
      • During building work, exposure to hazardous materials should be addressed
      • Impact of waste management
      • Process for in-place management of exposure risks for existing buildings
      • Pesticide use
      • Reduction in use of hazardous materials used in building materials
      • Careful selection of cleaning products
      • VOC emissions must be controlled to specific limit levels – short and long term
  8. Mind

    Mental health is addressed within this standard, and the impact the indoor environment can have on mental health. As a prerequisite, good mental health should be promoted through education and initiatives. In addition:

        • Access to nature should be facilitated through the design of the building
        • Mental health support services should be made available
        • Stress support should be provided and restorative opportunities, spaces and programs for employees should also be facilitated
        • Focus and sleep support be provided
        • Business travel should be planned with the employee’s mental health in mind
        • Addiction support services should be available, together with an opioid emergency response plan.
  9. Community

    The Community element of this standard is aimed to support new parents in access to essential healthcare, workplace health promotion and accommodation. A prerequisite for this is first promoting awareness of health and wellness. Other requirements include:

    • Integrative design, including all stakeholders in the design of a building so that it functions as a collaborative space for all
    • An occupant survey to establish the self reported health and well being of the occupants Health policies and health promotion should be adopted, including immunization efforts Support for the family is recommended, and specifically for new parents and new mothers Individuals should be encouraged to get involved in their community and buildings should be accessible for all
    • Individuals should be supported to have emergency management plans in place
    • Housing should be allocated on an equitable basis.
  10. Innovations

    While the WELL standard is significantly comprehensive, it also recognises the importance of continued evolution, this is reflected in the section on Innovation. Buildings are recognised for continuous evolution of the WELL standard and those that engage a WELL Accredited Professional to support their certification process. This section always promotes on-going education in terms of the standard taking steps towards deeper commitments to health and wellness. This section also rewards those projects that have achieved certification under leading green building rating systems.


  1. Cradle to Cradle

Cradle to cradleCradle to Cradle certification is based on certification of products, and is one of the Certification programs recognised in the WELL standard. Its vision is a prosperous economy where safe materials are intelligently manufactured in ways that positively impact people and the planet. There are 5 criteria that they measure, and dependent upon the level at which a product adheres to or exceeds requirements, a range of categories can be awarded which include Basic, Bronze, Silver, Gold and Platinum.


Material Health is the only section of this standard that will have a direct impact on those suffering from asthma and allergies and is summarised in Table 1, similarly to the WHI certification, there is no measure of the biological sources of indoor air contamination.


  1. Material HealthUse of well established restricted substances should be avoided. Avoidance of organohalogens are specifically identified. The material’s chemical composition should be provided, the more comprehensive this is, the higher the grade awarded. As the chemical composition becomes more defined, each of the chemicals can be assessed to determine their level of hazard/risk. All this information can be then utilised to try to identify materials that may be more compatible with human health and the environment, with products subsequently produced from these more preferred materials. This standard specifically identifies VOCs as being important to control in terms of emission as well as content. Finally, this standard encourages the reduction and elimination of non-desirable chemicals throughout the supply chain.
  2. Product Circularity

    The components of the product that are of biological origin or may be recycled have been identified, in addition to any barriers there may be to their application in a circular use. These barriers should also be addressed, identifying mitigating options. The processes or methods should be publically available, in order to increase the likelihood of their re-use/recycling. Materials for use in the product should be selected specifically on their potential to be re-cycled/re-used, and to achieve circularity, materials that have already been cycled should be prioritised for use in products. Product disassembly should be considered in manufacture of product; the greater the ease of disassembly, the greater likelihood for re-cycling. The manufacturer should also engage in active cycling, putting in place internal processes to facilitate this, rather than relying on external providers.

  3. Renewable Energy and Climate

    The facilities in which the product is manufactured must comply with air emissions legislation, as well as defining an understanding of the product’s energy and carbon impact. In addition, opportunities to address any of these impacts must be addressed. In line with this, the company must develop a renewable energy and climate strategy. As part of overall aims, dependent upon level desired, companies should also identify renewable sources of energy to be used in the manufacture of the product, as well as addressing greenhouse gas emissions from same. The amount of greenhouse gas emissions produced as part of the entire manufacturing process, and how this should be offset should also be addressed. Where blowing agents are used, they should be certified as not contributing to climate change or depletion of the ozone layer.


  4. Water Stewardship

    Water needs to be treated as a valuable resource, and so the local and product relevant water issue should be understood. Effluent must be in compliance with regulations and the amount of water used should be quantified. Manufacturing facilities should provide adequate drinking water, sanitation and hygiene facilities. A water stewardship strategy should be developed, outlining how the company will operate in a way that protects water as a natural resource. Water conservation technologies should be adopted and water usage should be transparent for review. The contribution of product specific chemicals to effluent should be assessed and optimised and the quality of the effluent should also be optimised. Projects should be undertaken to promote the positive impact of water stewardship on aquatic ecosystems.

  5. Social Fairness

    This final part of the standard deals with corporate social responsibility. Risks associated with human rights should be assessed across the supply chain and a human rights policy should be established. Performance with regards to human rights should be assessed and a strategy for policy implementation should be developed. Commitment to this process should be demonstrated and a management system should be adhered to. The business should put in place system where employees can safely report the negative effects of business activities on social fairness, and all these process should be transparent and engage relevant stakeholders. The positive impact of these initiatives should be communicated through various projects. Industry wide collaboration is encouraged and a culture of social fairness should be fostered within businesses.


  1. GreenguardGreenguard Gold

Greenguard Gold certification is operated by Underwriters Laboratories (UL) and is used for a range of products, including building materials, furniture and furnishings. The certification is focussed on low chemical emission products. There are two types of certification for these classes of products, the Gold certification is based on a more extensive list of chemicals and stricter VOC emission levels.

The Certification Standard for chemical emissions for buildings materials, finishes and furnishings defines the chemicals and limit levels that must be achieved in order to be awarded certification. Products are tested according to well established methodologies and are applicable to the office, home and educational environments. Limit levels are defined for total chemicals emitted (volatile organic compounds; VOCs) and for individual chemicals. The time points for measurement of these VOCs is between 7 and 13 days.  This certification is only focussed on material contribution to indoor air quality (summarised in Table 1) and does not address any biological elements.


  1. ClearchemClearchem

Clearchem is a certification program operated by Berkeley Analytical and focusses in a similar way to Greenguard Gold. The certification is for products that are used to construct or finish building interiors. The standard specifically focusses on volatile organic compound emission from these products. Clearchem also allows for self declaration, where VOC testing may have already been carried out in recognised laboratories, re-testing is nor required.

The Clearchem standard is aligned with the California Department of Public Health (CDPH) standard method for VOC analysis. It measures total VOCs over periods of 11, 12 and 14 days, in addition to measuring VOCs of specific concern, such as formaldehyde. This certification is only focussed on material contribution to indoor air quality (summarised in Table 1) and does not address any biological elements.


  1. DeclareDeclare Certification

Declare Certification is operated by the International Living Future Institute. (ILFI) Its goal is to positively change the materials marketplace by offering simplicity and ease of use to both manufacturers and specifiers, to facilitate the exchange of information and enable a future of healthier buildings. In this context, in a similar way to WHI and Cradle to Cradle, Declare operates a more holistic approach to material health. This certification is only focussed on material contribution to indoor air quality (summarised in Table 1) and does not address any biological elements.

The program focusses on a number of imperatives including:

  • Healthy Interior Performance – compliance with CDPH (outlined above, and similarly to Clearchem)
  • Red list – products may not contain chemicals contained on the Red List (such as asbestos, bisphenol A and Phthalates)
  • Responsible sourcing – this is focussed at wood products, and ensuring that these have been sustainable extracted. This may be proven by third party certification (Forest Stewardship Council) or by meeting ILFI’s definition of low risk or salvaged wood.


  1. Indoor AdvantageFloor ScoreIndoor Advantage and Floorscore

Indoor Advantage and Floorscore are operated by Scientific Certification Systems (SCS). SCS partner with a range of stakeholders in the area of third party environmental, sustainability and food quality certification, auditing, testing and standards development. While the Indoor Advantage Certification is for building materials and furniture, the Floorscore  certification is focussed only on flooring products. They are indoor air quality standards, and so are just concerned with compounds that may enter and affect indoor air. At a minimum, products certified by SCS must achieve limit levels set out by CDPH; these are based solely on VOC levels at specified time points. Additional claims that may be made can be supported by testing to a range of additional standards such as Canadian VOC Concentration Limits for Architectural Coatings, European Decopaint Directive (2004/42/EC) or additional testing (eg methylene chloride and perchloroethylene). This certification is only focussed on material contribution to indoor air quality (summarised in Table 1) and does not address any biological elements.


  1. asthma & allergy friendly Certification Program logoasthma & allergy friendly® Certification Program

The asthma & allergy friendly® Certification Program  is operated by Allergy Standards Ltd in collaboration with the Asthma and Allergy Foundation of America (AAFA), Asthma Society of Canada (ASC) and is also operated internationally through a global certification mark. The certification program addresses a range of consumer products, focussed on their impact on indoor health, from a chemical and biological perspective.

In the context of building materials and finishes the program includes certification for paint, flooring, HVAC filters, cleaning products and insulation. Certification for chemical compliance is similar to the previous programs, however the asthma & allergy friendly® Certification Program requires VOC and specific chemical emissions to meet stringent levels at earlier time points (to reflect user and inhabitant exposure). In addition for products such as filters and cleaning products, their impact on biological compounds such as allergens and micro-organisms is also assessed, with associated criteria for certification. This program is entirely focussed on products that may be more suitable for those suffering from asthma and allergies.


  1. Environmental Product DeclarationEnvironmental Product Declaration

Environmental Product Declaration is an independently verified and registered document that communicates the life cycle environmental impact of a product. Documents are completed in accordance with ISO 14025 and deposited in publically available database. EPDs can be used to help businesses respond to procurement requests, communicate to the consumer and to other businesses.

A life cycle assessment is carried out on the designated product, verified, and these are compiled into the EPD. The focus of EPD therefore is primarily impact on the environment; within the life cycle assessment the type of information that is required includes:

  • Use of non-renewable primary energy
  • Use of renewable primary energy
  • Depletion of fossil energy resources
  • Depletion of mineral resources.
  • Use of renewable resources
  • Use of fresh water
  • Use of land resources
  • Waste
  • Global warming potential (GWP)
  • Ozone depletion potential (ODP)

            This certification does not include any elements of direct relevance for those suffering from asthma and allergies.


  1. Health Product DeclarationHealth Product Declaration Collaborative

Health Product Declaration Collaborative is a member association of building industry organisations. Their purpose is to improve the transparency of information and the material health of the built environment. As an overview, the standard that has been developed by the HPDC requires reporting of product contents and associated health information. This means that the materials that are used within the product must be defined, along with any health effects. The sources for reporting of health hazards are recommended as the GreenScreen for Safer Chemicals and the HPD Priority Hazard List  The HPD do not carry out any testing themselves, but rely on third party certification to adhere to the requirements of the standard, under specific guidelines. This certification is only focussed on material contribution to indoor air quality (summarised in Table 1) and does not address any biological elements.


  1. U.S. Green BuildingLeadership in Energy and Environmental Design (LEED)

Leadership in Energy and Environmental Design is operated by the United States Green Building Council. It is one of the longest running green building certification programs. It began in the United States but is now a globally utilised standard. LEED rating consists of 5 different areas addressing multiple projects:

  • Building Design and Construction
  • Interior Design and Construction
  • Building Operations and Maintenance
  • Neighborhood Development
  • Homes

These areas are divided up and points are awarded with certification awarded based on points achieved (Certified, Silver, Bronze, Gold). The minimum requirement that are required to be met are:

  • Be in compliance with environmental regulations and standards
  • Must meet the threshold of floor area requirements
  • Meet a minimum of building occupancy in terms of number of users
  • Maintain a reasonable site boundary
  • Be a permanent building
  • Share energy and water usage data
  • Must have a minimum building to site area ratio

Sections with the LEED Program that are of relevance for those suffering from asthma and allergies include promoting indoor air quality, and Materials and Resources. Within the Energy and Atmosphere section however, the focus appear to be primarily on energy conservation, rather than good indoor air quality. LEED’s materials requirements are summarised in Table 1.

Within each of the areas, the project must meet certain goals and conditions. These are aligned with goals of LEED and are

  • Location and transportation – The applicant should take account of the location of the project and how transportation will affect users of the building.
  • Materials and Resources- Products that are more sustainable and environmentally friendly should be selected, in addition to reducing waste and promoting better quality indoor air.
  • Water efficiency – the design of the building should take into account the most efficient way of utilising and re-using water.
  • Energy and atmosphere – the building should be energy efficient and promote indoor air quality.
  • Sustainable sites – The selection of the site and design of the building should be complementary, to minimise pollution.
  • Indoor environmental quality – The best use of natural light should be encouraged and natural ventilation should be promoted.
  • Innovation – new ideas are welcomed that are not covered under the five LEED main areas.
  • Regional priority credits – If the region has a specific need or concern, the project should address this.

Each of these Certification Programs has its own particular focus and ethos and consumers will utilise whichever program reflects their own concerns and buying influence. The WHI and Cradle 2 Cradle programs take a holistic approach to a building, including such aspects as impact on mental health, the community and innovation. Specific environmental aspects are built into the standards of the WHI, Cradle 2 Cradle, Declare, Environmental Product Declaration and LEED. In terms of a building’s impact on the environment, it is clearly a very useful signpost for both developers and home owners to receive this kind of direction. Environmentally friendly is not always human friendly however.

In terms of indoor air quality, the materials used in the building’s life cycle (and their VOC emissions) and the ventilation system, will have the most tangible impact on indoor air quality. Nearly all certification programs have a requirement around materials, and their impact on the built environment and occupants. All listed certification programs have aligned their testing and limit levels to the California Department of Public Health at a minimum, and some have additional requirements.

Volatile Organic Compounds

Emission of volatile organic compounds is an important aspect of indoor air quality, and particularly so for those suffering from asthma and allergies. There is no ideal test for VOCs; those developed are designed to best mimic real life conditions, however none are perfect. The CDPH limit for VOCs addresses individual VOC emissions (for 35 chemicals), rather than total VOCs (TVOCs). The reasoning for this is that TVOCs measurement are based on measuring VOCs as a function of a toluene standard and so will not be exact. CDPH therefore have selected 35 VOCs of concern, and that is what their testing is based on. While this does have validity, measurement of TVOC does also; if TVOCs are higher than limit levels, even if this is not exact, it can draw attention to areas that need to be addressed.

The majority of Certification Programs above predominantly address VOC testing levels in two ways, TVOCs required to be less than 0.5 mg/m³ (500 μg/m³) at 14 days and  less than 0.3 mg/m3 (300 μg/m3) at a time point not later than 28 days (gold level), or specific limit levels for individual VOCs. The asthma & allergy friendly® Certification Program has the most stringent requirements for TVOCs with requirements of less than 0.5 mg/m³ at 24 hours, 0.2 mg/m³ at 48 hours and 0.075 mg/m³ at 336 hours (14 days) for paints. The reason for the requirements at earlier time-points is based on in-use risks; for example if an inhabitant paints their bedroom, it is much more desirable if the VOC levels reduce as rapidly as possible. In addition, for those who are sensitive to VOCs, lower limit levels can create a more healthy indoor air environment. Similarly for many of the individual VOCs the asthma & allergy friendly® Certification Program has much lower limit levels to reflect the more sensitive cohort that they represent; eg formaldehyde 1.65μg/m³ at 336 hours compared to ≤10 μg/m³ for some programs.

The asthma & allergy friendly® Certification Program is the only certification program outlined that specifically focusses on this more chemically sensitive cohort, and takes into consideration biological contaminants, in addition to chemical ones, in the context of buildings and building materials. HVAC filters need to be capable of the removal of allergens in addition to maintaining air flow during use; cleaning products must be capable of removing allergens and micro-organisms; fiberglass insulation must be resistant to fungal growth.

A summary of how the various certification programs compare on materials requirements is outlined below:

Table 1: Summary of chemical and biological testing required by Building and Building Material Certification Standards. 


Chemical Requirements

Biological Requirements



Restricted substances list

VOC requirement aligned with CDHP, Cradle to Cradle, Declare


Cradle 2 Cradle

Cradle to cradle

Restricted substances list

VOC requirements aligned with CPDH in addition to TVOC requirement


GreenGuard Gold



No Restricted substances list

VOC requirement aligned with CPDH, in addition to TVOC requirement




No Restricted substances list

VOC requirement aligned with CPDH, in addition to TVOC requirement




Restricted substances list

VOC requirement aligned with CPDH


Indoor Advantage

Indoor Advantage

No Restricted substances list

VOC requirement aligned with CPDH



Floor Score

No Restricted substances list

VOC requirement aligned with CPDH


asthma & allergy friendly®

asthma & allergy friendly Certification Program logo

Restricted substances list

VOC requirement aligned to CPDH in addition to more stringent TVOC requirement eg paint

0.5 mg/m3 at 24 hours

0.2 mg/m3 at 48 hours

0.075 mg/m3 at 336 hours

Control of exposure to allergens and micro-organisms at certain thresholds and/or the ability to remove allergens and micro-organisms at certain levels.


Health Product Declaration

Restricted substances list

VOC requirement aligned with CPDH, Greenguard Gold, Indoor Advantage and Floorscore



U.S. Green Building

No Restricted substances list

VOC requirement aligned with CPDH


In terms of those suffering from asthma and allergies, more specific care is often required in the selection of building materials, design of buildings and subsequent fit out and use. Products that may be suitable for the general public may not be suitable for more sensitive individuals. While there are many comprehensive certification programs, their impact on indoor air quality for health, as opposed to environmental impact should be carefully considered.

Dr. Tim Yeomans photo

Dr. Tim Yeomans

About the author 

Thanks to Dr. Tim Yeomans for this insightful article.

Dr. Tim Yeomans is the Centre Manager for Shannon Applied Biotechnology Centre, a collaboration between two third level colleges in Ireland. Tim holds a PhD in Microbiology and postgraduate qualifications in Technology Commercialisation and Innovation Management. Tim has worked in research and development for 20 years, both in industry and academia. In his role in Shannon ABC, Tim is responsible for the scientific direction of the Centre, intellectual property management and business and technology development.


asthma & allergy friendly®, Allergy Standards, allergies, asthma, building materials, certification program, indoor air, indoor environment, indoor air quality, allergen, sensitivities.


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