Shippers' "moral sanctions" against Russian trade are unprecedented "in human history."

As a rule, the shipping industry has ignored sanctions.Since Russia's invasion of Ukraine, companies are choosing self-sanctioning.

In the past, "moral sanctions" in the shipping and commodities industries have been rare, say experts.

On the week of the Ukrainian invasion, Shell bought Russian crude oil.

Announcing its regret, ExxonMobil pledged to "use alternatives to Russian oil whenever possible."

Energy giant's reaction is one of many "moral sanctions" imposed by the West after Russia invaded Ukraine

Ami Daniel, CEO of maritime risk consultancy Windward, told Insider that companies have historically done the bare minimum sanctions