Basis for a safe design: COSSMA

Risk assessments consider end use exposure but may not consider other stages of the product life cycle. Chemical hazard assessments provide a standard to compare human and enivronmental impacts. Chemicals with lower ineherent hazard will generally have less risk.

Beauty and personal care products are typically assessed by evaluating the risk they could pose to a consumer based on anticipated exposure to the product. This involves finding the critical health effect for each ingredient and ensuring that the product is safe for its intended use. Risk assessments typically consider the end use exposure but may not consider other stages of the product life cycle. For example, a body lotion may be evaluated to look at human health concerns from application to the skin and found to be safe for that intended use, but its potential environmental impacts after being rinsed off may not be evaluated. Failure to look at the potential environmental toxicity and fate could be missed when only evaluating human health risks based on intended use.

To resolve this potential information gap and provide additional detail on human and environmental endpoints, chemical hazard assessments (CHA) are useful tools for characterising chemicals and providing a standard to compare hazard profiles of ingredients to one another. They can be used to support clean beauty or sustainability claims while companies work to shift the inherent hazard profiles of their ingredient portfolio to safer ingredients with lower inherent hazard. Chemicals with lower inherent hazard will generally have less risk through the supply chain and product life cycle.

figure 1: Moving the bell curve of ingredients based on inherent hazard. figures: Chemforward

Safe and sustainable design

While many ingredients are characterised with established safe use levels by government regulators (Echa¹ Reach²), or industry groups (CosmeticIngredient Review) the full chemical hazard profile is often incomplete. A risk assessment will often confirm the safe use of these chemicals; however, a comprehensive chemical hazard assessment can help distinguish between different “levels” of inherent safety.

A full chemical hazard assessment includes classifications for a comprehensive suite of human health endpoints, as well as classifications for environmental toxicity and fate. Many of the criteria and endpoints for hazard classification are derived from the Globally Harmonized System of Classification and Labelling (GHS)³. Additional criteria such as those defining a chemical’s persistence, potential for bioaccumulation and ability to interfere with the endocrine system supplement what has been standardised with GHS.

This detailed classification allows users to differentiate between a chemical that is safe for its intended use from a human health perspective and alternative chemicals that have inherently lower azard profiles. CHAs are increasingly seen as a tool to aid product developers in establishing a palette of ingredient options that can support clean beauty trends and enable more informed decision making.

CHAs are used to identify hazards associated with a chemical and help to answer the question, “how do the hazards compare among ingredient options?”. It is not an alternative to risk assessment but rather, it is a complementary tool in the toolbox for making informed decisions.

figure 2: Sample GHS hazard table. Classifications are based on the Globally Harmonised System of Classification and Labeling of Hazards (GHS) Rev 8: Cat = Category (1, 1A, 1B, 2, 3, etc.); NC = Not classified (equivalent to low hazard using GHS criteria); CNP = Classification Not Possible (no data available); Colour coding: Red: Category is accompanied by GHS Signal Word ‘Danger’; Orange: Category is accompanied by GHS Signal Word ‘Warning’; Yellow: Category is accompanied by no GHS Signal Word; Green: Not Classified; Confidence indicators: Bold text: High confidence; (Italic text in parentheses): Low confidence; Plain text: Classification not possible. figures: Chemforward

A phased approach

CHA and risk assessment can be used in a phased way. One approach is to apply chemical hazard assessment criteria to screen out chemicals of concern when formulating products. Chemicals that are known to have hazards of high concern such as carcinogenicity or reproductive or development toxicity, or chemicals that are both persistent and toxic can be ruled out as ingredient candidates based on hazard properties alone. While there may be conditions under which such chemicals can be used safely, it is a basic premise of green chemistry that it is better to focus on eliminating chemical hazard than it is to rely on controlling exposure, since risk is a function of hazard and exposure.

Another approach is to use CHA to compare candidate ingredients based on their hazard profiles to identify inherently safer options to shift the overall hazard of ingredients, as illustrated in figure 1, to optimise health and environmental outcomes. After identifying and introducing safer alternatives to product formulations the risk assessment paradigm can be applied to ensure that even the least hazardous ingredients are being used safely. This phased approach helps to raise the bar for safe ingredients while leveraging the power of risk assessment.

Quality and continuous improvement

Chemical hazard data is used to drive decisions that affect individuals, businesses, and societies. Given the impact of these decisions, there must be a heightened focus on ensuring the highest level of trust in the data. Decisions based on inaccurate or incomplete chemical hazard data perpetuate the cycle of regrettable substitution and consumer mistrust.

A centralised online platform of chemical hazard assessments4 is designed to support users in selecting safer chemical ingredient alternatives. Chemicals in the database are populated with hazard profiles and users can search for chemicals and compare different chemical hazard scores of chemicals with similar functions and applications.

The process for conducting a CHA in the system starts with a qualified assessor, that searches the available literature on a chemical. Where there are data gaps, these experts use new approach methods such as non-animal test methods and read across to fill data gaps. Instead of finding the criticaleffect as in a risk assessment, the assessor enters summary data for each hazard endpoint and classifies the hazard based on a defined standard such as GHS. The platform also classifies hazards using the material health assessment methodology as defined in Cra-dle to Cradle⁵ (C2C) certification.

The same data is used for both methods but the differences in criteria allow for insightful contrast between GHS and the more precautionary C2CC method, as well as the inclusion of additional endpoints not covered under GHS. Along with the classification of the endpoint, assessors indicate confidence in the classification and provide a rationale to justify their classification. After the CHA is complete:

All CHAs undergo verification by external 3rd party toxicology experts before they are published to the platform.
Results are displayed in two hazard summary tables on the user end.
Results display overall chemical ratings including the hazard band

References:

¹ Echea: European chemicals agency

² Reach: Registration, evaluation, authorisation, and restriction of chemicals)

³ Globally Harmonized System of Classification and Labeling of Chemicals (GHS Rev. 9, 2021) https://unece.org/transport/standards/transport/dangerous-goods/ghs-rev9-2021

⁴ ChemForward, www.chemforward.org

⁵ Cradle to Cradle Certified Material Health Assessment Methodology Feb. 2022 https://www.c2ccertified.org/resources/detail/material_assessment_methodology