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Bisphenol A (BPA) is used in the production of plastic but has oestrogenic activity. Therefore, BPA substitutes, such as fluorene-9-bisphenol (BHPF), have been introduced for the production of so-called ‘BPA-free' plastics. Here we show that BHPF is released from commercial ‘BPA-free' plastic bottles into drinking water and has anti-oestrogenic effects in mice. We demonstrate that BHPF has anti-oestrogenic activity in vitro and, in an uterotrophic assay in mice, induces low uterine weight, atrophic endometria and causes adverse pregnancy outcomes, even at doses lower than those of BPA for which no observed adverse effect have been reported. Female mice given water containing BHPF released from plastic bottles, have detectable levels of BHPF in serum, low uterine weights and show decreased expressions of oestrogen-responsive genes. We also detect BHPF in the plasma of 7/100 individuals, who regularly drink water from plastic bottles. Our data suggest that BPA substitutes should be tested for anti-oestrogenic activity and call for further study of the toxicological effects of BHPF on human health.

Organic photocatalytic atom transfer radical polymerization (ATRP) has recently become a research highlight. Organic photocatalysts based on phenothiazine, phenoxazine, and phenazine have been reported and exhibited remarkable performance. All of those structures contain two heteroatoms, which makes the oxidative state (i.e., the radical cation) of the photocatalysts stable enough to complete the catalytic cycle. However, despite the similar structure, 9,9-dimethyl dihydroacridine (DHA) was rarely used for constructing photocatalyst due to its unstable oxidative state. DHA is a weak electron donor that was widely applied in blue-emitting thermally activated delayed fluorescence (TADF) molecules. Its weaker electron-donating ability will contribute to a higher energy level of the excited state. Also, the higher oxidation potential of its radical cation will contribute to better controllability due to fast reversible dormancy. In this study, we found that substitution on the active sites of DHA could make it stable enough to be the donor part of a donor–acceptor (D–A)-type photocatalyst for ATRP. Moreover, chemical modification is necessary for both stabilizing the radical cation and improving the controllability in the polymerization process. Further modification was made to construct a rapid equilibrium between initiation and reversible dormancy, and polymerization with quantitative initiator efficiencies was achieved with a polydispersity of 1.14. It is notable that such modification can probably apply to different kinds of electron donors, and various organic chromophores could thus be applied to construct organic photocatalyst with superior performance.

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