National Rendering Day

History of National Rendering Day

National Rendering Day was officially launched on April 21, 2023. The North American Renderers Association (NARA), in partnership with National Day Calendar, created it to raise awareness about the role of rendering in sustainability.

This date was chosen to connect with Earth Day, which falls on April 22, highlighting the environmental benefits of repurposing materials that might otherwise go to waste.

Rendering transforms unused animal parts and used cooking oil into useful products like renewable fuels, pet food, and agricultural supplies. Without this process, tons of organic material would pile up in landfills, creating pollution. Instead, rendering helps conserve resources and reduces the need for new raw materials.

NARA introduced this annual event to spotlight the industry’s contributions to reducing waste and supporting a circular economy. Many people don’t realize how much rendering helps keep food waste out of landfills. This special day encourages learning about the process and its impact on sustainability.

Since its start, the event has gained attention across industries, sparking discussions about responsible resource use.

It reminds businesses and individuals alike that sustainability isn’t just about recycling bottles and cans—it’s also about finding value in things often overlooked. National Rendering Day celebrates a process that quietly benefits the environment every day.

Facts About National Rendering Day

Global Rendering Prevents Hundreds of Millions of Tons of Emissions

Modern rendering plants worldwide recycle animal byproducts and used cooking oils in a way that significantly cuts greenhouse gas emissions.

One life cycle assessment estimated that if these materials were landfilled or otherwise discarded instead of rendered, global emissions would rise by at least 200 million metric tons of CO₂-equivalent each year, largely due to methane from decomposition and the need to produce replacement materials from virgin resources.  

Rendered Fats Are a Major Feedstock for Renewable Diesel and SAF  

Used cooking oil and tallow from rendering have become key feedstocks for renewable diesel and sustainable aviation fuel (SAF).

In the United States, renewable diesel capacity has grown rapidly since the mid‑2010s, and the Energy Information Administration notes that a large share of this growth depends on waste fats and oils, which have lower lifecycle carbon intensity than virgin vegetable oils and help refiners meet low‑carbon fuel standards.  

Rendering Supplies More Than a Third of Ingredients in Some Pet Foods

In the pet food industry, rendered meat and bone meals, poultry byproduct meals, and animal fats supply concentrated protein and energy that would otherwise be wasted.

Industry and academic nutrition data show that in many commercial dry dog and cat foods, rendered ingredients can make up 30 to 40 percent of the formula by weight, providing essential amino acids, minerals like calcium and phosphorus, and highly palatable fats for companion animals.  

Ninth‑Century Soapmaking Already Relied on Rendered Fats

Long before industrial chemistry, people were rendering animal fat to make soap.

Historical records from the early Middle Ages describe boiling animal tallow with alkaline ashes to produce cleaning bars, and by the ninth century, cities like Nablus and Aleppo had organized soap industries based on rendered fats and oils.

This early use of byproducts laid the groundwork for today’s oleochemical sector, which still depends heavily on rendered materials.  

Modern Rendering Achieves High Recovery Rates from Slaughter Waste 

In contemporary meat processing, nearly every part of an animal that is not eaten can be recovered through rendering.

Technical reports from North American and European industries indicate that 40 to 50 percent of the live weight of cattle, hogs, and poultry is inedible for humans; rendering recovers most of this fraction as usable fats and proteins, turning what would be a massive disposal problem into inputs for fuels, feeds, and industrial products.  

Rendered Byproducts Feed Livestock and Close Nutrient Loops

Rendered protein meals are widely used in livestock, poultry, and aquaculture feeds, where they replace part of the demand for soymeal and other plant proteins.

Research compiled by the Food and Agriculture Organization notes that animal byproduct meals supply highly digestible amino acids and minerals, and when added to feed rations at appropriate levels, they help recycle nutrients from slaughter byproducts back into food production instead of relying solely on newly cultivated crops.  

Germany’s 19th‑Century “Glue and Tallow” Factories Marked a Turning Point

The industrialization of rendering accelerated in 19th‑century Europe, where specialized “glue and tallow” works appeared to handle slaughterhouse waste.

In cities like Berlin and Hamburg, these facilities used high‑pressure steam cooking and closed vessels to process bones, hides, and offal into glues, lubricants, candles, and soap stock, reducing urban waste and odors while creating a distinct sector that anticipated today’s centralized rendering plants.