How our system of accepted substances works

Hazardous substances in IT products are a risk to human health and the environment. Criteria in TCO Certified aim to reduce or eliminate the use of these substances, drive transparency and develop pathways to safer alternatives.

Simply banning substances isn’t enough. We need better information about the substances that are being used to replace them. With TCO Certified, a chemical is considered a high risk until it is proven to be otherwise. GreenScreen® and ChemForward® are used to identify a pathway to safer alternatives.

Since 2015, our methodology has been to consider all substances as high risk until their effects on human health and the environment are independently assessed. We started with flame retardants, and have since added plasticizers and stabilizers used in products, and cleaning ingredients and cleaning products used in manufacturing.

For compliance with TCO Certified, only substances that achieve a GreenScreen benchmark score of 2, 3 or 4 or a ChemForward hazard band A, B or C set by an independent Licensed Profiler are added to TCO Certified Accepted Substance List and may be used in certified products and their manufacture.

A list of safer substances

Our list of substances approved for use in certified products and production.

Potential candidates list

Find substances previously approved as safer by independent toxicologists.

Independent assessment

Currently, GreenScreen® and ChemForward® are the licensed profilers used. They offer an objective, scientific way of assessing potential effects and identifying safer alternatives to the most hazardous substances.

Developed by the US-based non-profit Clean Production Action, GreenScreen provides a structured approach to evaluating human health and environmental safety data for a variety of chemical substances. Once a substance is assessed in accordance with these risks, the GreenScreen methodology assigns it to one of five possible Benchmark scores, based on the level of concern.
ChemFORWARD assesses chemicals under two reputable chemical hazard assessment methodologies: GHS and Cradle to Cradle CertifiedⓇ (C2CC); the results of which are translated into an overall Chemical Rating representing the highest applicable hazards associated with the chemical. All ChemFORWARD assessments are completed and maintained by qualified assessor firms and peer-reviewed by independent toxicologists. Hazard banding is a simple summary score on an A-F scale.

GreenScreen benchmarks and ChemForward hazard band assessments are valid for up to five years. TCO Certified Accepted Substance List is dynamic and substances may be re-assessed in light of new scientific findings. A substance must be re-assessed before the expiry date, otherwise it will be moved to the potential candidate list and can no longer be used for certified products.

Guidelines for TCO Certified Accepted Substance List

How to add a chemical to the list

  1. Submit a valid assessment report from:
    • an independent, licensed GreenScreen (GS) profiler, or
    • a ChemForward (CF) qualified assessor.
  2. Accepted assessments are valid for five (5) years from the assessment date. This date is displayed on TCO Certified Accepted Substance List.
  3. The following assessment scores are accepted:
    • GreenScreen (GS) Benchmarks: 4, 3, and 2.
    • ChemForward (CF) Hazard Bands: A, B, and C.
  4. We accept that the alignments between GS Benchmarks and CF Hazard Bands are:
    • Benchmark 4 corresponds to Hazard Band A.
    • Benchmark 3 corresponds to Hazard Band B.
    • Benchmark 2 corresponds to Hazard Band C.
  5. Only one chemical per unique CAS Registry Number (CASRN) is listed, with the following exception:
    • Polymeric substances with different scores must be validated separately before being added to the list.

Updating an assessment

  1. Updated assessments of a substance by the original licensed profiler showing an unchanged score (benchmark or hazard band) are accepted up to six (6) months before the original assessment’s validity expires.
    • The original profiler will be contacted first to confirm the requester of the original assessment wishes to have it updated.
  2. Assessments from other licensed profilers showing an unchanged score are accepted up to four (4) months before the original assessment’s validity expires.
    • In this case, the chemical will be marked as: “Approaching Expiration Date” four months before the expiry date.
  3. Updated assessments of a substance by the original licensed profiler showing an unchanged score (benchmark or hazard band) are accepted up to six (6) months before the original assessment’s validity expires.

Changing or challenging a GS Benchmark or CF Hazard Band based on new information

To ensure chemical information remains accurate and up to date, challenges to valid GreenScreen (GS) benchmarks or ChemForward (CF) hazard bands can be made during the 5-year validity period of an assessment. Challenges must be supported by an updated assessment reflecting a revised score, either improved or degraded.

  1. When the updated assessment is from the original profiler organization:
    • If the updated assessment comes from the same licensed profiler, the new information will replace the existing assessment on TCO Certified Accepted Substance List. This reflects the profiler’s revised rationale in light of new data.
  2. When the updated assessment is from a different profiler organization:
    • If the updated assessment is submitted by a different licensed profiler and shows a different score for the same CASRN, it is treated as a conflicting challenge to the existing valid assessment.
  3. Resolution of conflicting assessments:
    • In cases of conflicting assessments, TCO Development will defer to the accepted hazard assessment framework (GreenScreen or ChemForward) for validation.
    • The framework will determine which assessment provides the correct score.
    • Once a decision is reached, any necessary updates will be made to TCO Certified Accepted Substance List.

Removing a chemical from TCO Certified Accepted Substance List

  1. Expiration of validity period:
    • If an updated assessment is not received by the end of the 5-year validity period, the chemical will be considered no longer in use.
    • The chemical will be moved to our potential candidate list, and its Benchmark or Hazard Band will no longer be shown, since it is no longer valid.
  2. Validated challenge with degraded score:
    • If a validated challenge during the 5-year validity period results in the Benchmark or Hazard Band being downgraded to a non-accepted score, the chemical will be removed from TCO Certified Accepted Substance List.
    • A sunset date will be established to allow users sufficient time to transition to a safer alternative listed on TCO Certified Accepted Substance List.

About our potential candidate list

This list presents substances that have been previously reviewed by toxicologists and have been identified as used for applications covered by TCO Certified Accepted Substance List. Previous assessments indicate that the substances may be classed as safer alternatives. However, to be added to TCO Certified Accepted Substance List, an updated assessment must be carried out and the substance must achieve a GreenScreen benchmark score of 2, 3 or 4 or a ChemForward hazard band A, B or C set by an independent Licensed Profiler.
If you are interested in seeing a substance added to TCO Certified Accepted Substance List or the potential candidate list, contact TCO Development or the profiler organization.