A Safe and Just Earth by Design.

Movement to a safe and just Earth system space for novel entities depends on the control of their quantities and/or qualities. Concerns about the adverse effects of such entities emphasize the momentous challenge of managing production and release volumes, but comparatively little attention has been paid to the control of novel entity quality (i.e., hazards). While control over chemical quantities may reduce exposure, if the inherent hazard has not been reduced or eliminated, even small quantities of hazardous substances can result in significant harm to the Earth system, people, and other forms of life if controls fail (which occur probabilistically). Such intraspecies, intergenerational, and intragenerational harm is unjust. Safer chemical design, which eliminates or reduces inherent hazards at the design stage while maximizing functionality, affords control over novel chemical entities and their adverse impacts. A large body of literature demonstrates that we can already manipulate the fate and transport, absorption, distribution, metabolism, excretion, and specific interactions of novel entities by adjusting their physicochemical properties. Safer chemical design, therefore, enables the elimination of significant harm to present and future generations as well as to other species and maximizes the functional performance of essential molecules and materials. The ability to act via safer chemical design is evident. Whether action is taken remains to be determined.