There’s a lot of synthetic products used in the manufacture of shoes and having done some hunting around I thought I might share some websites of brands O think are worthwhile looking at:
Some review information can be found here: Better Shoes Foundation
@Alex_Beckett. I can totally recommend the Vivo Barefoot “Bloom” shoes. They are made from some sort of Algae Based foam 
. I didn’t buy them for environmental reasons. I just wanted some shoes that I could wear without socks and these seemed like a crazy idea. Turned out they were brilliant. Super comfortable. They have just started wearing through the sole after 2 and a half years of nearly continuous use.
These are my vivobarefoot shoes… I have been wearing these for 2 years at work, cycling too and from etc… They’re water tight and have been awesome. They’re also the only pair of shoes which have prompted a stranger to ask me where I got them.
Couldn’t recommend this company more- have another pair of work shoes and walking bootstrap as well. They’re sustainably sourced, seriously comfortable, long lasting and are helpful for posture etc (as they’re barefoot)!
I have bought lots of pairs of shoes over the years from Vegetarian Shoes. they have a shop in Brighton but they do webshop orders as well. I’ve had no reason not to go back for more (I think I must have had about 10 pairs from them). I believe some of their shoes are made at a workers co-operative in Portugal. The vegetarian aspect was what was important to me, especially 10 years or so ago when it was a bit more of an alien concept than it is now. The one criticism is that the synthetic materials they use tend to make my feet quite hot and sweaty…! https://www.vegetarian-shoes.co.uk/
I have also bought Ethletic shoes. They were sensibly priced and seemingly very ethically made. https://ethletic.com/en/
I tend to buy second hand shoes now, which allows me to switch off/lower my ethical concerns a little. Rightly or wrongly I lower my ethical standards with second hand goods, as I consider the impacts of manufacturing/production and transport of new goods. Plus it’s definitely the cheapest option! There seems to be no end of decent second hand clothing and shoes available at low prices, which I guess is a consequence of the general addiction to fast fashion.
I think the gold standard for ethically produced shoes are the Adbusters Blackspot Unswooshers… but they’re not cheap! I would definitely like a pair though.
I’ve just ordered a pair of Primus Lite trainers from Vivobarefoot. I had to send the POZU ones back as they were too narrow. Vivobarefoot have given me this link to send on to anyone who makes an order for over £100 to save them £25…https://vivobarefoot.mention-me.com/m/ol/ac3jq-alexander-beckett
