Goodbye Endocrine Disruption!

By Shivanthi Sriskandha, Member-at-Large for the GCI

A recent study published in the Royal Society of Chemistry journal, Green Chemistry, has aimed to bridge the gap between chemists and toxicologists in the design of safer, sustainable chemical products. The paper is authored by 23 scientists in the fields of green chemistry, biology, and environmental health science, and proposes a protocol to effectively develop compounds that will not cause endocrine disruption.

Oral contraceptives contain a combination of estrogen and progestogen, known EDCs that have implications on fish and other wildlife.

Endocrine disruption occurs when an agent or mixture of chemicals interferes with any aspect of hormone action. Common endocrine-disrupting chemicals (EDCs) include BPA, DDT, flame retardants, and phthalate-containing products. As such, the primary concern is exposure to these chemicals in consumer products. Research has now shown that EDCs can affect human metabolism, liver, and bone function as well as have an impact on diabetes, obesity, infertility, and learning disorders.

Currently, environmental performance and sustainability are not taken into account when designing new chemicals, or at least not emphasized enough. Furthermore, chemists have a limited knowledge of toxicology and therefore aren’t trained to evaluate toxicity risks. For these reasons, the Tiered Protocol for Endocrine Disruption, or TiPED, system was invented to guide chemists towards the design of safer materials.

Pesticides and herbicides used for agricultural and domestic purposes are common sources of EDCs.

The 5-tiered TiPED system combines principles in green chemistry with new methods of toxicology to form a comprehensive system that will evaluate a new chemical’s toxicity. The system is designed so that the user has the ability to enter the process at any stage in order to best meet the user’s needs. In each tier, a pass-fail grade is given to the chemical in question. If it passes, it is allowed to move onto the next stage for further testing. If it fails, it must go back to the drawing board to be reassessed. Since the current protocol cannot detect all possible mechanisms of endocrine disruption (an area of science that is still in progress), updates to the protocol will be made on the peer-reviewed TiPED website as they are developed.


The proposed tiered test for endocrine disruption, TiPED.[1]

Here’s how the Tiers work:

  • Tier 1: Computational approaches that can assess the chemical compound by searching existing databases for known EDCs and by predicting endocrine-disrupting behaviour using computer models.
  • Tier 2: Cell-based assays that directly test a chemical’s ability to interact with and affect the activity of targeted proteins, hormone receptors, and genes.
  • Tier 3: Assesses the activity of a test chemical on an endocrine-signaling pathway that may lead to cell division, differentiation or death, or to endocrine-mediated processes.
  • Tier 4: Determines chemical impacts on fish and amphibian reproductive cycles, development and behaviour.
  • Tier 5: Mammalian testing to mimic responses in humans.

Overall, consumer awareness of the harm in commercial products is leading to the development of safer chemicals and greater collaboration between various scientific disciplines to make our world a healthier place.

For further information, please see the companion website: where you can gain access to the paper and consult the formal protocol on the TiPED system.


[1] T. T. Schug et al., “Designing endocrine disruption out of the next generation of chemicals”, Green Chem. 2013, 15, 181-198.

Shut It Campaign

By Nadine Borduas, Member-at-Large for the GCI

If you happen to be visiting the Davenport Wing in the Department of Chemistry at U of T, you will notice along the side of each fumehood a ruler with hues of orange and grey with thumbs pointing up and down. Why? Well, because the fumehoods in Davenport are variable-flow fumehoods! In other words, the flow through the fumehood is dictated by the sash height. The higher the sash → the higher the flow → the higher the energy consumption → the lower the thumb. It also implies that if everyone had their fumehoods wide open, the energy consumption would actually exceed the energy of the constant-flow fumehoods in Lash Miller and invalidate the variable-flow technology as a green alternative. So, how did the GCI intervene to help ensure that variable-flow fumehoods were being kept at optimal heights?

We launched an ongoing "Shut It" campaign to encourage optimal fumehood sash heights!

We launched an ongoing “Shut It” campaign to encourage optimal fumehood sash heights!

Back in 2008, the Sustainability Office (SO) at U of T had run a campaign to “Just Shut It”. The campaign was launched to minimize the energy consumption of the variable-flow fumehoods in the Davenport Wing. Over the course of approximately a year and a half, SO ambassadors inspected the fumehoods and rewarded complying students.

There are two ways to comply: 1) if you’re not at your fumehood, it should be shut below 3 inches, and 2) if you are working at your fumehood, its height shouldn’t exceed 14 inches. The SO team analyzed the data and published the result of the campaign in the International Journal of Sustainability in Higher Education. Pretty impressive research!

What is most notable in this article, in my opinion, is a graph showing the compliance percentage over time. The sash height compliance during the campaign was about 80%, but eight months later, termed post-campaign, it was back down to 20%! The lack of compliance after the campaign may be due to the lack of incentives and to the quick turnaround of students in the department. So the GCI, a sustainable group of students that will hopefully be around for years to come, decided to launch a campaign, where you would have no “post-campaign” syndrome and consequently maintain high levels of energy savings.

With the help of GCI inspectors (Peter, Ian, Christine, Ran, and myself), we toured the Davenport Wing from July to September, stamping smiley faces on complying fumehoods. Kai Wan form the Morris Group was awarded a Tim Horton’s gift card for having perfect compliance over the fifteen inspections, and the Zamble Group won a free pizza lunch for having the best compliance on a group basis.

We hope the organic, bio-organic, and inorganic students of the Davenport Wing enjoyed the challenge and will continue to “just shut it”. Stay tuned for the continuation of this campaign in 2015 as well!