The other type of oil spill

News outlets reported significant oil spills in Sweden and Norway this week. But there was no sign of goopy black crude - because this was vegetable oil.

Vegetable oil spills have been recorded for at least 50 years, but have only recently started gaining public attention as the need for decarbonization has led to a shift from fossil to biofuels, turbo-charging demand.

Vegetable oils are primarily transported at sea with tanker ships, which has an inherent risk of spills. The vegetable oil trade is projected to grow for the next few decades, and the risk of spills will also grow.

Vegetable oil spills are often biodegradable, but the flip side is that this involves intense bacterial respiration that consumes huge amounts of oxygen, creating dead zones. There are other environmental impacts:

• Waterfowl drown because of loss of buoyancy. They can also die of exposure due to loss of insulating capacity of feathers or starvation if their food sources are destroyed.
• The oils coagulate and settle to the bottom, destroying benthic organisms like shellfish.
• Oil accumulates on the gills of fish, suffocating them. It also coats or kills plankton and algae that are important sources of fish food.
• Some constituents of the oil or its metabolites may have a direct toxic effect on aquatic organisms. Vegetable oils with high concentrations of free fatty acids (e.g., crude palm oil) are thought to be sufficiently soluble to kill fish.
• Polymerization-oxidation reactions cause the oils to form heavy sludges that contaminate shorelines and beaches.

There are legal consequences for companies responsible for vegetable oil spills. For example, the U.S.A.'s Oil Pollution Act of 1990, implemented after the Exxon Valdez disaster, does not give a precise definition of oil. As a consequence vegetable oil spills in the U.S. are regulated similarly to petroleum oil.

We don't usually think of our food as a pollutant, but spilling large amounts of vegetable oils is detrimental for the environment. Vegetable oils are a key component of the global food system and important inputs to many industries. In many cases there are no viable substitutes for these oils.

With this context, what are we to do? Active investors can take two steps:

1. Ask companies for transparency. Global Reporting Initiative (GRI) disclosure 306-3 for significant spills is a good first step on their part.
2. It is important to ensure facilities have well developed spill prevention and response plans, even when not mandated by law. Spills will happen, but research shows that having good prevention and response plans makes a substantial difference in the extent subsequent environmental impacts. Ask your companies if they have them at their facilities!

References

Muthalia A, et al. (2022) The degradation and toxicity of commercially traded vegetable oils following spills in aquatic environment. Environmental Research 214:113985.

Pereira MG, Mudge SM, Latchford J (2003) Polymerisation versus degradation of sunflower oil spilled in the marine environments. Marine Pollution Bulletin 46:1078-1081.

Bucas G, Saliot A (2002) Sea transport of animal and vegetable oils and its environmental consequences. Marine Pollution Bulletin 44:1388-1396.

Davis BD, et al. (2002) Response plans for animal fat and vegetable oil facilities. International Oil Spill Conference Proceedings 2001:257-262.

Gunstone FD, ed. (2002) Vegetable Oils in Food Technology: Composition, Properties and Uses. CRC Press.

Calanog SA, et al. (1999) Preliminary evaluation of potential impacts of non-petroleum oils on the aquatic environment. International Oil Spill Conference 1999:597-605.

Rigger D (1997) Edible oils: Are they really that different? International Oil Spill Conference 1997:59-61.

Mudge SM (1995) Deleterious effects from accidental spillages of vegetable oils. Spill Science & Technology Bulletin 2:187-191.

Smith DW, Herunter SM (1989) Birds affected by a canola oil spill in Vancouver Harbour, February 1989. Spill Technology Newsletter 14:3-5.

Crump-Wiesner HJ, Jennings AL (1975) Properties and effects of nonpetroleum oils. Conference on Prevention and Control of Oil Pollution 1975:29-32.