Principles & requirements

Project Developers shall demonstrate that they comply with all principles and requirements outlined in the Rainbow Standard Rules, and described below with a specific focus on BioCCS.

Rainbow Standard Rules

Additionality

Project Developers shall follow the additionality requirements in the Rainbow Standard Rules and fill out the Rainbow Additionality Template.

Regulatory surplus analysis shall demonstrate that there are no regulations that require or mandate project activities. It is acceptable if regulations promote or set targets for these activities, because the resulting increase in activities shall be accounted for in the baseline scenario.

At the European Union level, projects automatically pass the regulatory surplus analysis, which has been conducted by the Rainbow Team. Project Developers are only required to provide a country-level regulatory surplus analysis.

Durability

Durability threshold

The durability of carbon removal for projects certified under this methodology is 1000+ years.

Reversal risk assessment

The major carbon reversal risks from BioCCS is at the CO₂ storage site in geological formations, where fugitive CO₂ leaks may occur due to e.g. natural or induced seismicity, lateral migration of the CO₂ plume, degrading confining systems, faults and fractures at infrastructure.

Project design requirements largely reduce reversal risks by restricting the eligible carbon storage to countries with established storage regulations.

In addition to storing CO₂ at a regulated storage site, Project Developers shall:

prove access to storage capacity for the projected amount of CO₂ captured during the facility's operating lifetime through contracts with storage providers,
prove compliance with national storage regulations (in the Storage Plan),
establish a post-crediting reversal monitoring plan (in the Storage Plan),

Upon meeting the above-mentioned requirements, the risk of reversal for carbon storage in geological formations is considered negligible. There are no further requirements to assess reversal risks at the project-level.

All projects certified under this methodology shall contribute the default minimum 2% of their verified removal RCCs to the Rainbow Buffer Pool, as defined in the Rainbow Standard Rules.

Storage Plan

The assumption that reversal risk is negligible in geological storage relies on storage sites being rigorously selected, characterized, and monitored, both during operations and after site closure. As part of the validation audit, Project Developers are required to provide a storage plan, including but not limited to the following information:

Section of Storage Plan

Required content

Site suitability

applicable regulations governing the geological storage site
characterization of the storage site (i.e potential storage complex and surrounding area),
assessment methods and data used to determine suitability for geological storage,
risk assessment for the potential of leakage from the storage site, including risk magnitude, timing and frequency.

Monitoring procedures

technologies used
frequency of monitoring
The list of monitored parameters shall at least comprise
- the gas flow rate,
- the chemical composition of the injected CO₂ stream
- the pressure and temperature at the injection wellhead, at the reservoir and/or along the well (where accessible)
Normal, alert and threshold values for monitored parameters procedures implemented in case the alert or threshold values are reached.

Reversal monitoring plan scope

Plans to monitor the injection facility, the storage complex, including the CO₂ plume where possible, and its surroundings, covering at least the following points:

changes in the actual and modeled behavior of CO₂,
any irregularities,
migration and leakage of CO₂,
negative effects on the surrounding environment,
structural integrity of the infrastructure,
location and extent of the area monitored

Reversal response protocol

Outlining actions taken if a reversal event is detected (i.e. timeline for response steps, corrective measures, documentation of any reversal events). This protocol shall be in accordance with the Rainbow Cancelation Procedure and its Cancelation Notice.

Project Developers shall establish an agreement with the storage operator to ensure compliance with the above mentioned requirements, if the Project Developer is not the storage provider.

Post-closure procedure

Description of procedures and liability transfer process, in accordance with applicable regulatory frameworks. This shall at least cover

post-closure monitoring,
reporting and corrective measures,
conditions for liability transfer.

Liability

In the case that the Project Developer is not the storage operator, the Project Developer shall provide a clear division of responsibilities and liabilities between the Project Developer and the external storage operator.

Note that all required information shall comply with the requirements from relevant local or national regulations. If such regulations do not provide specifications, it shall be based on industry best practices or peer-reviewed scientific literature.

No double counting

Project Developers shall sign the Rainbow MRV & Registry Terms & Conditions, committing to follow the requirements outlined in the Rainbow Standard Rules, including not double using or double issuing carbon credits.

BioCCS projects have multiple process steps, with each step potentially operated or managed by parties other than the Project Developer. To avoid double counting, Project Developers shall provide proof, through contracts with all parties involved in the supply chain, that they are the sole owner of the RCCs associated with the storage activity, and ensure that no other party claims carbon removals associated to the activity.

Any allocation applied for co-products in the GHG Quantification section of this methodology shall be consistent with any other GHG accounting performed by the operator, whether voluntary or required under applicable law. Specifically, this means that removals assigned to the BioCCS activity shall not also be deducted or claimed as avoided in a product carbon footprint, Environmental Product Declaration, or corporate GHG inventory for the primary product(s).

CO₂ Traceability

Mass balance for non-segregated streams

If the project CO₂ is mixed with CO₂ from other sources at any point after leaving the capture site, the CO₂ injected at the storage site cannot be directly linked to the BioCCS project. In the case of this so-called non-segregated stream scenario, Project Developers shall use contractual agreements with the transport and/or storage operators to link a quantity of CO₂ being injected at a storage site with an equivalent quantity of CO₂ captured at the capture site by the BioCCS project (minus any transport and storage losses), even if the exact physical location of the captured CO₂ molecules is unknown. No other CO₂ stored or leaving the shared system shall be linked to the same captured quantity.

Project Developers shall provide evidence, or arrange for the transport and/or storage operators to provide it, showing that all of the following mass balance rules are met:

Each quantity of CO₂ entering the transport or storage system can only be counted as stored or discharged once.
The total CO₂ entering any transport segment or storage site in a given period must equal the total CO₂ leaving or being stored at that same segment or site in the same period. Small differences are allowed to account for CO₂ actively in transit or undergoing storage processes at the end of the period, and for measurement uncertainty.
Where CO₂ from a project is mixed with CO₂ from other sources, and the mixed stream is then split across more than one transport segment or storage site, Project Developers shall agree with other parties which portion of the transferred CO₂ is treated as coming or partially coming from the BioCCS project.
Where CO₂ is transferred into a shared transport network and mixed with CO₂ from other sources, Project Developers do not need to track the exact transit time. Any equivalent quantity of CO₂ leaving the network after the project's CO₂ entered may be treated as the project's CO₂, as long as the CO₂ is not assumed to have traveled against the flow direction.

For example, a BioCCS project at a biogas facility captures 1,000 tCO₂ and injects it into a shared pipeline network already carrying CO₂ from two other industrial sources.

The three CO₂ streams mix in the pipeline. It's not possible to track exactly which molecules came from the BioCCS project.

Applying the methods to calculate transport losses, 8 tCO₂ associated with the project CO₂ was lost in transit. Under a contractual agreementt, the BioCCS project and the storage site operator agree in writing that:

992 tCO₂ injected at the storage site is attributed to the BioCCS project (1,000 t captured minus 8 t transport losses)
That 992 tCO₂ is counted as permanently stored by the BioCCS project
No other party can claim those same 992 tCO₂ as their stored quantity

The contract doesn't require the BioCCS project to prove its specific CO₂ molecules are the ones stored, just that the mass balance adds up and no double-counting occurs across all users of the shared system

Co-benefits

Projects should support at least two quantifiable and verifiable environmental or social co-benefits, aligned with the UN Sustainable Development Goals (SDGs) framework. Any co-benefits claimed by the Project Developer shall be quantified, monitored, and audited for each verification and credit issuance.

Common co-benefits under this methodology are detailed in the table below. Project Developers may suggest and prove other co-benefits not mentioned here.

SDG 13 on Climate Action by default is not considered a co-benefit here, since it is implicitly accounted for in the issuance of carbon credits. If the project delivers climate benefits that are not accounted for in the GHG reduction quantifications, then they may be considered as co-benefits.

Table 1 Common co-benefits that projects under this methodology may provide are detailed, including types of proof that can be used to justify each co-benefit.

UN SDG

Example

Proof

SDG 7.2. Increase the share of renewable energy in the global energy mix.

BioCCS projects classified as greenfield projects produce renewable bioenergy (heat, electricity, biogas), and contribute to increasing the share of renewable energy.

Energy produced (kWh), injection receipts from electricity/heat/gas network

SDG 9.4: Upgrade infrastructure and retrofit industries to make them sustainable.

Retrofits and additions to existing facilities support sustainable industrialization by operating scalable, innovative carbon-negative solutions.

Project description

SDG 11.6: Reduce adverse environmental impact of cities

By capturing flue gas from municipal solid waste management sites, BioCCS projects may capture harmful pollutants alongside CO_2, thereby improving urban air quality.

Analysis and quantification of captured flue gas

SDG 12.2: Achieve sustainable management and efficient use of natural resources.

BioCCS project capturing CO₂ from waste-only biomass ensures that no additional land or resources are required for feedstock. This approach maximizes resource efficiency, avoids competition with food production and promotes circular economy principles.

Biomass invoices and supplier contracts

Environmental and social safeguards

Project Developers shall prove that the project does not contribute to substantial environmental and social harms.

Projects shall follow all national, local and European (if located in Europe) environmental and social regulations for the capture, transport and storage of CO₂, and prove such compliance using, for example, permits, certifications, or licenses.

Project Developers shall comply with the following biomass sustainability requirements, and complete the BioCCS risk assessment described below.

Biomass sustainability

The following requirements apply to all biomass fractions:

Project Developers shall transparently report on the mass, type and source of biomass to the level required in regulations, national guidance and relevant industrial standards.
Project Developers shall prove that biomass complies with the requirements for different types of biomass outlined below.

Forestry waste

Eligible sources of forestry waste and downstream wood processing waste are:

Secondary forest: Natural but not primary old-growth forest, may still be managed for timber
Managed forest: Managed mixed-use forests that may include agroforestry, plantations or rotational logging

Forestry waste and downstream wood processing waste shall meet all of the following requirements:

Biomass shall not be sourced from a primary forest.
Biomass shall be proven to be waste, following the proof of waste status requirements below.
Biomass shall hold at least one of the following forestry sustainability certificates:
- FSC (Forest Stewardship Council)⁠
- PEFC (Program for the Endorsement of Forest Certification)⁠
- RSB (Roundtable on Sustainable Biomaterials)⁠
- SFI (Sustainable Forestry Initiative)⁠
- SBP (Sustainable Biomass Program)⁠
Biomass shall be sourced from an area with stable or increasing carbon stocks. Assessment of forest carbon stocks shall be evidenced by one of the following approaches:
- Sourcing area assessment: An independent third-party assessment demonstrating that the net change in forest carbon stocks within the sourcing region has not decreased during the last five years for which data is available, compared to the average forest carbon stocks in the previous 5-year period. The assessment shall be based on public inventory data and shall include live, above-ground biomass. Deadwood pools may be included if reliable data is available.
- Jurisdictional assessment: Evidence that the net LULUCF emissions of the jurisdiction, as reported to the UNFCCC, are zero or negative (i.e. a net carbon sink) over a rolling average not exceeding 10 years, using the most recently available primary data. Net emissions shall include both forest land and harvested wood products as reported within the LULUCF sector. Where biomass is sourced from jurisdictional territories exceeding 5 million km², additional evidence that forest carbon stocks in the sourcing are not decreasing over the same period shall be provided.

Necessary tree removal

Necessary tree removal from any forest includes damaged trees, or trees removed for planned forest management such as preventing disease spread or wildfires.

Project Developer shall

prove that the biomass comes from a necessary tree removal activity. Evidence includes official documentation from a competent governmental authority confirming the necessity of tree removal, stating the forest health objective (such as fire risk reduction, pest control, or disease containment), together with chain-of-custody records linking the biomass to the designated intervention area, and
prove that the biomass is classified as waste, following the proof of waste status requirements below, and
provide an Ecosystem Restoration Plan outlining all of the following:
- the extent of tree removal, and how much biomass is left on the ground after harvesting
- impacts on biodiversity and habitat loss
- impacts on ecosystem carbon loss

Agro-food waste

Agro-food waste may originate from the field, or from food processing facilities. It shall be proven to be waste, following the Proof of waste status requirements below.

If agro-food waste originates from the field, it shall be harvested in a way that preserves soil carbon stocks and soil quality. Evidence may include national or regional regulations, policies or local residue harvesting plans, provided these include some form of monitoring and enforcement.

Municipal solid waste (MSW)

Municipal solid waste shall not be generated for the purpose of generating CO₂ and/or for CDR.

MSW sites shall prove sustainable management of any hazardous waste, following the applicable regulations.

The biomass shall also be proven to be waste, following the proof of waste status requirements below.

Municipal sludge

Municipal sludge such as sewage sludge and biosolids shall not be generated for the purpose of generating CO₂ and/or for CDR.

Sites handling municipal sludge shall prove sustainable management of any hazardous waste, following the applicable regulations.

The biomass shall also be proven to be waste, following the proof of waste status requirements below.

Animal waste

Animal waste such as manure and slurry shall not be generated for the purpose of generating CO₂ and/or for CDR.

The biomass shall also be proven to be waste, following the proof of waste status requirements below.

Invasive species

Project Developers shall provide proof of invasive species status for any biomass feedstock categorized as invasive species. This may include but is not limited to peer-reviewed scientific literature documenting the species as invasive in the specific region, national or regional government invasive species lists or registers, regional intergovernmental lists (e.g. IUCN Invasive Species Specialist Group database), or local official weed management orders.

Project Developers shall provide an Ecosystem Restoration Plan, outlining all of the following:

the extent of invasive species harvesting, and how much biomass is left in the field after harvesting
procedures to ensure only targeted invasive species are harvested
impacts on biodiversity and habitat loss
impacts on ecosystem carbon loss

Marginal energy crops

To avoid competition with food and feed production, marginal energy crops are defined as crops that are:

grown on marginal, degraded or contaminated land, not suitable for food or feed production; or
grown as a cover crop or intermediary crop, on agricultural land suited for food and feed production.

Project Developers shall demonstrate compliance with the following sustainability criteria:

The classification of land as marginal, degraded or contaminated shall be recognized by a local competent authority.
Marginal energy crops shall not be cultivated on land classified as highly biodiverse land, or high carbon stock land in or after January 2008. Land use maps, land register extracts or other official documentation shall be provided as evidence.
Marginal energy crops shall be cultivated under an agronomic monitoring or management plan that preserves or improves soil quality and soil carbon. Acceptable proof includes national or regional regulations, policies or local harvesting plans, provided these include some form of monitoring and enforcement.
Cultivation of intermediary or cover crops shall comply with applicable local or regional regulations governing the cultivation of this crop type for bioenergy applications, ensuring that the crop is not the primary driver of land use and does not trigger demand for additional land. Acceptable proof includes feedstock traceability records, identifying each feedstock batch by plot of origin and delivery date. Access to feedstock sourcing history at farm level shall be made available upon request.

Primary energy crops

Primary energy crops are grown as a main crop on agricultural land that is suited for food and feed production.

This biomass type is eligible only for BioCCS projects capturing CO₂ from anaerobic digestion, and shall not exceed 15% of the total mass of the feedstock mix.

Project Developers shall demonstrate compliance with the following sustainability criteria:

To avoid competition with food and feed production, primary energy crops shall be grown on land that was in repeated cultivation for energy crops for at least 20 years prior to the project start date.
Primary energy crops shall not be cultivated on land classified as highly biodiverse land, or high carbon stock land in or after January 2008. Land use maps, land register extracts or other official documentation shall be provided as evidence.
Primary energy crops shall be cultivated under an agronomic monitoring or management plan that preserves or improves soil quality and soil carbon. Acceptable proof includes national or regional regulations, policies or local harvesting plans, provided these include some form of monitoring and enforcement.

Proof of waste status

Biomass types categorized above as waste shall be proven to be waste using any one of the following three methods:

Price: if Project Developers did not pay for the biomass, or if they were paid to handle it, the biomass can be considered waste. Acceptable proof includes invoices, receipts, or contracts.
Contextual analysis: Project Developers may submit an analysis supported by reputable sources that the biomass 1) could not be used as main material products, and 2) was not grown for the purpose of CDR or bioenergy generation.
Positive list of wastes: if the biomass is included in the following list, it can be considered waste. Acceptable proof includes invoices, receipts, contracts, or photographic evidence and is required for validation:

sawmill residues
sawdust
shavings
bark
forestry tops and branches
wildfire management residues
straw
husks

corn cobs
wood pruning from horticulture
nut shells
bagasse
sugar beet pulp
municipal solid waste
municipal sludge and biosolids
animal manure and slurry

🇪🇺 CRCF requirement: Biomass sustainability

In addition to meeting all requirements outlined above, Projects seeking certification under the CRCF shall also comply with the following:

RED-certified biomass

Project shall use biomass that is compliant with the EU's Renewable Energy Directive (RED) III. Specifically, this means that

biomass shall be compliant with the sustainability requirements set out in Article 29 of the RED for the purposes referred to in Article 29, Paragraph 1 (a), (b) and (c), even if the project does not generate renewable energy that is taken into account under the RED.
the requirements on GHG savings set out in Article 29, Paragraph 10 shall only be met if the CO₂ is captured at a facility producing heat, electricity or a biofuel, bioliquid or biogas. The GHG savings criteria apply to the product of the facility.
biomass from waste or residues from agricultural, aquaculture, fisheries and forestry residues are subject to the sustainability requirements set out in Article 29, Paragraphs 2 to 7. Other biomass types are not subject to the requirements in these paragraphs.

Compliance shall be demonstrated by certification of the biomass from

voluntary schemes approved by the Commission in accordance with Article 30, Paragraph 4 of RED, or
national schemes recognized by the Commission in accordance with Article 30, Paragraph 6 of RED, or
schemes recognized by the competent national authority in the state where the BioCCS capture facility is located.

Additional biomass sustainability requirements

Project Developers shall also demonstrate that

biomass is not identified as being produced from a high indirect land use change risk feedstock, as defined in the Delegated Regulation 2019/807 to the RED.
if biomass is sourced from areas designated by the national competent authority for
conservation, including areas covered by the national restoration plan established under
Regulation (EU) 2024/1991, or in habitats that are protected, the sourcing shall be in
accordance with the conservation and restoration objectives for those areas.

CO₂ captured from energy production covered under RED

If CO₂ is captured from an energy production process covered by the RED, Project Developers shall demonstrate that

the national implementation of that directive applies to the operator of the energy production process and that the operator complies with this national implementation.
the operator complies with any measures in that national implementation that ensure that woody biomass is used according to the list of priorities established in Article 3, Paragraph 3 of the RED, including any derogations introduced by Member States under Article 3, Paragraph 3 (a), if the operator benefits from a relevant support scheme for energy production.
the operator does not receive direct financial support from Member States for the use of saw logs, veneer logs, industrial grade roundwood, stumps and roots to produce energy, in line with Article 3, Paragraph 3 (c)

Facilities regulated under the RED undergo periodic assessment of compliance with the sustainability requirements by Member State competent authorities. This periodic assessment shall not prevent the compliance assessment conducted by the VVB for approval of credit issuance. In practice, this means that the VVB does not need to wait for the completion of an ongoing RED assessment of compliance before assessing the BioCCS project and approving credit issuance. However, if the Member State assessment results in any non-conformity with Article 29 of the RED, Project Developers shall notify Rainbow and the VVB immediately.

Voluntary compensation of biomass

To support the regeneration of natural carbon stocks used for the generation of permanent carbon removals, Project Developers may purchase carbon farming sequestration units and report the amount in the monitoring report.

Biomass conversion efficiency

For projects that capture CO₂ from a facility that primarily converts biomass to heat and/or electricity, Project Developers shall not make operational changes that reduce the efficiency of the biomass-to-bioenergy conversion process, i.e. requiring greater biomass consumption in favor of higher CO₂ generation.

Project Developers shall prove one of the following:

The facility's nameplate energy generation capacity has not increased by more than what is needed to power the capture process. This shall be assessed relative to the facility's nameplate capacity either at the time it began operating, or three years prior to the start of the project's certification period.
The facility would remain economically viable without carbon removal, if it is
- a newly-constructed facility that became operational not more than one year before the start of the BioCCS project; or
- a facility that previously consumed fossil fuel feedstock, either partly or entirely, and that was adjusted to increase the share of biomass in the feedstock mix not more than one year before the start of the BioCCS project.

The above requirements do not apply if the project captures CO₂ from:

waste-to-energy facilities combusting wastes or residues other than agricultural, aquaculture, fisheries, and forestry residues (e.g. municipal waste incineration);
facilities using biomass for non-energy applications or where heat/electricity are not the primary outputs (e.g., biofuel or biogas production);
facilities using biomass as part of an industrial chemical process to produce a product other than heat or electricity, even if energy is also extracted.

Example

A bioenergy plant, built in 2015, has a nameplate energy generation capacity of 50 MW, which has remained unchanged since it began operating. In 2022, the facility was retrofitted with a carbon capture unit, which requires 3 MW of energy to operate, and captures 18,000 tCO₂/year. The plant consumes 100,000 tonnes/year of woody biomass.

Scenario 1: The plant’s nameplate capacity increased by 3 MW, from 50 MW (2019, three years prior to the start of the project) to 53 MW, due to an increased consumption of biomass. The capacity increase exactly matches the energy needed to power the capture process. No other operational changes were made.
- ✅ This scenario is eligible because the increase only covers the energy demand of the capture unit.
Scenario 2: The plant’s nameplate capacity increased by 6 MW, from 50 MW (2019) to 56 MW, exceeding the 3 MW required for the capture process. Since the increase is greater than what is needed to power the capture unit, it suggests that biomass consumption was increased not only to power the capture unit, but also to generate more CO₂ for capture.
- ❌ This scenario is ineligible because the capacity increase goes beyond the needs of the capture process.
Scenario 3: In 2025, the Project Developer installs an additional heat recovery system that improves the plant's overall thermal efficiency, allowing more CO₂ to be captured from the same flue gas stream. Biomass consumption remains unchanged at 100,000 tonnes/year, but the capture unit can now process a greater share of the flue gas, increasing captured CO₂ to 20,000 tCO₂/year
- ✅ This scenario is eligible. Although the operational changes increased CO₂ generation per unit of output, this results from an improvement in process efficiency, not from additional biomass consumption

A biogas plant produces biomethane through anaerobic digestion of agricultural residues. CO₂ is captured from the upgrading process, where it is separated from the raw biogas stream. The plant's primary output is biomethane for grid injection. In 2024, the plant increases its feedstock consumption by 20%, from 50,000 to 60,000 tonnes/year of agricultural residues, in order to produce more biomethane. As a result, more CO₂ is available for capture.

✅ This scenario is not subject to the requirements above. The facility's primary purpose is biomethane production, not heat or electricity generation. The additional CO2 captured is a co-product of biomethane production expansion, not the result of an operational adjustment made solely to increase CO₂ availability.

Environmental and social risk assessment

Project Developers shall fill in the BioCCS risk assessment template, to evaluate the identified environmental and social risks of projects. The identified risks include:

For biomass

Disruption of soil health when collecting and exporting organic matter
Deforestation from use of forestry products as feedstock
Distant transport of feedstock inputs (>100 km)

For CCS

Generation of hazardous liquid and solid wastes and exhaust gases during capture process
CO₂ stream impurities
CO₂ leakage during transport
CO₂ migration or leakage to surface or near-surface at storage site
Contamination of groundwater due to leakage of CO₂ from storage reservoir
Induced seismicity

🇪🇺 CRCF requirement: Risk assessment

Project Developers seeking compliance with the EU's CRCF shall additionally evaluate and address the following risks.

Climate change adaptation

To comply with the do-no-significant-harm to climate change adaptation criteria, Project Developers shall identify the physical climate risks that are material to the project from those listed in Section II of Appendix A to Annex 1 of the Commission Delegated Regulation (EU) 2021/2139 and perform a robust climate risk and vulnerability assessment following the steps outlined in Section I of that same appendix.

Sustainable use and protection of water and marine resources

Any potential risks due to the project to the good status or the good ecological potential of bodies of water, including surface water and groundwater, or to the good environmental status of marine waters. In the case that pollutants that are scrubbed from flue gases in order to reduce air pollution may be released to a body of water, the air pollution benefit and the availability of alternative discharge strategies shall be taken into consideration when evaluating the impact on water quality.

Addressing the following Minimum environmental and social risks defined in the Rainbow Standard Rules is equivalent to addressing this risk:

Minimize pollutant discharges to water, noise and vibration
Avoid and/or minimize negative impacts on terrestrial and marine biodiversity and ecosystems
Minimize water consumption and stress in the project

Circular economy, efficient use of sustainably sourced bio-based materials

Any potential risks to the circular economy objectives from the projects, considering

the project leads to significant inefficiencies in the use of materials or in the direct or indirect use of natural resources such as non-renewable energy sources, raw materials, water and land at one or more stages of the life cycle of products, including in terms of durability, reparability, upgradability, reusability or recyclability of products
the project leads to a significant increase in the generation, incineration or disposal of waste, with the exception of the incineration of non-recyclable hazardous waste
the long-term disposal of waste may cause significant and long-term harm to the environment

Pollution prevention and control

Any potential risks to generate a significant increase in the emissions of pollutants to air, water or land from the project. Where facilities are within the scope of Directive 2010/75/EU they shall comply with all requirements arising from that Directive.

Where facilities are not in the scope of that Directive, addressing the following Minimum environmental and social risks defined in the Rainbow Standard Rules is equivalent to addressing this risk.

Minimize pollutant emissions to air
Minimize pollutant discharges to water, noise and vibration
Minimize generation of waste and release of hazardous materials, chemical pesticides and fertilizers

Protection and restoration of biodiversity and ecosystems

Any potential risks from the project to the good condition or resilience of ecosystems or to the conservation status of habitats and species, including those of Union interest or to the achievement of targets or obligations set out in national restoration plans established under Regulation (EU) 2024/1991.

Addressing the following Minimum environmental and social risks defined in the Rainbow Standard Rules is equivalent to addressing this risk. Note that any potential risk to targets or obligations in national restoration plans shall be addressed separately.

Avoid and/or minimize negative impacts on terrestrial and marine biodiversity and ecosystems
Protect the habitats of rare, threatened, and endangered species, including areas needed for habitat connectivity
Do not convert natural forests, grasslands, wetlands, or high conservation value habitats
Minimize soil degradation and soil erosion
Minimize water consumption and stress in the project

Project Developers shall assign a likelihood and severity score of each risk, and provide an explanation of their choices. The VVB and Rainbow’s Certification team shall evaluate the assessment and may recommend changes to the assigned scores.

Any identified material risk (defined as issues with a risk score of moderate or higher) shall be subject to a Risk Mitigation Plan, which outlines how Project Developers will mitigate, monitor, report, and if necessary, compensate for any environmental and/or social harms.

Additional proof may be required for certain high risk environmental and social problems.

The Project Developer, the Rainbow Certification Team, or the VVB may suggest additional risks to be considered for a specific project.

Note that the life-cycle GHG reduction calculations account for the climate change impacts of most environmental risks. Nonetheless, Project Developers shall transparently describe any substantial and sensitive GHG emission risks in the risk evaluation template.

All risk assessments must also address the Minimum environmental and social risks defined in the Rainbow Standard Rules.

Leakage

According to the Rainbow Standard Rules, carbon removal projects shall minimize leakage, where carbon-emitting activities are displaced or shifted outside of the project boundary.

Project Developers shall assess and, if identified to be material, quantify the leakage caused by the BioCCS project. This shall be done by first identifying the alternative fate of biomass, and then assessing the leakage risks from the following identified leakage sources:

Counterfactual carbon storage
Diversion of biomass
Indirect land use change
Diversion of bioenergy and biomaterial

Biomass-related leakage requirements (leakage sources 1-3) apply to the following biomass fractions:

Greenfield:
- Biomass fraction allocated to CO₂ generation
- Parasitic load biomass fraction
Retrofit:
- Baseline biomass fraction (if used for parasitic load)
- Additional biomass fraction

Any leakage GHG emissions are calculated according to the Leakage emissions section and deducted from the project GHG quantification.

The leakage assessment is valid for 5 years, provided the biomass type and sourcing region remain unchanged. After 5 years, upon verification, a new leakage assessment shall be conducted for the project with updated context and proof.

The Project Developer is responsible for reporting any significant change in biomass type or sourcing region in their monitoring report at each verification. Where such a change is identified, a reassessment of leakage impacts is required, even if the project's 5-year leakage assessment is still valid.

Alternative fate of biomass

Project Developers shall evaluate the most likely alternative use/s of the biomass in order to assess leakage risks associated with the counterfactual carbon storage and the diversion of biomass. The assessment shall be transparent and conservative.

Alternative uses of the biomass include but are not limited to:

incineration
energy combustion
left on field / in forest
animal bedding

animal feed
mulching
landfill
other (specified by Project Developers)

Proof shall be provided and may include signed statements from the biomass provider, historical records from the biomass provider, regional statistics or reputable reporting.

A short list of likely alternative uses may be provided for descriptive purposes, but for the purpose of further analysis, one single alternative use shall be proposed.

Counterfactual carbon storage

The climate benefit of a BioCCS project, i.e. the actual removal of CO₂ from the atmosphere, only occurs when the carbon in the biomass feedstock would have been released to the atmosphere in the absence of the project. In other words, for the period that carbon would have remained stored in the biomass in its alternative use/counterfactual scenario, any project CO₂ permanently stored represents CO₂ that would not yet have been emitted.

The timing of this release depends on the type of biomass and its alternative fate. It can be rapid, where the counterfactual involves fast decay or combustion, or it can span decades, as with woody biomass in cool or dry environments.

Although these decay timescales are negligible relative to the 1,000+ year durability of BioCCS carbon removal, only the removal of biogenic CO₂ otherwise released in the near-term is additional and can be credited. This ensures that the project delivers a near-term benefit for climate change mitigation.

The assessment of counterfactual carbon storage is informed by the biomass's alternative fate scenario:

No baseline carbon storage is considered for feedstock whose alternative fate fully releases its carbon in the near-term. This includes
- incineration
- energy combustion
- necessary tree removal under a wildfire mitigation program.
For all other alternative fate scenarios, counterfactual carbon storage is assumed to be non-negligible and shall be quantified according to the Counterfactual carbon storage section in the GHG Quantification.

Diversion of biomass

BioCCS projects capture CO₂ from sustainable biomass, a scarce resource, that may otherwise have been used elsewhere. Demand from the project's activity risks displacing biomass from an existing use, forcing other actors to use high-emission alternatives.

Leakage from the diversion of biomass feedstock can be assumed to be negligible if Project Developers can demonstrate one of the following cases:

Description

Proof

The project is a retrofit and the biomass feedstock consumed by the project did not change in quantity compared to the business-as-usual scenario over the last 3 years prior to retrofitting.

Calculation of the baseline consumption rate

The feedstock is agricultural or forestry waste that would have been burnt on the field or elsewhere.

Historic proof of disposal from feedstock supplier (e.g. contract with disposal or end-use sites)

The feedstock is whole trees from necessary tree removal and is unsuitable for bioenergy or material production.

Justification and proof of

necessary tree removal
unsuitability for bioenergy and material production

Historic proof of disposal from feedstock supplier (e.g. contract with disposal or end-use sites)

If none of the cases can be demonstrated, leakage from the diversion of biomass shall be quantified for each feedstock type and source according to the rules set out in the Diversion of biomass section of the GHG Quantification and deducted from the total GHG removals of the project.

Indirect land-use change

Indirect land use change can occur when land that was previously used to produce food or feed is converted to produce biomass for bioenergy. As the demand for food and feed still needs to be met, this can lead to agricultural land being extended into areas with high carbon stocks, such as forests, wetlands and peatlands, causing additional emissions.

Projects that use any fraction of biomass input that derives from oil palm plantations and soybean cultivation are ineligible due to the high risk of indirect land-use change (iLUC) associated to this feedstock type.

Project Developers shall quantify iLUC leakage emissions following the rules in the Indirect land use change section of the GHG Quantification, where required by the table below.

Biomass type

iLUC risk

Forestry waste