Report Looks at Risk of Biodiesel on Human Health

By Gary G. Pearl, DVM, Clemson University Adjunct Professor

The Canadian Minister of Health has published the final report, Human Health Risk Assessment for Biodiesel Production, Distribution, and Use in Canada. This has been a lengthy and extensive project conducted by the Fuels Assessment Section of the Water, Air, and Climate Change Bureau in the Health Environments and Consumer Safety Branch of Health Canada. The focus has been on human health aspects with emphasis on environmental effects that may provide human health risks associated with the use of biodiesel as an alternative combustible fuel.

The document consists of 224 pages of text; 21 pages listing tables, acronyms, and abbreviations; and the reference section. The Fats and Proteins Research Foundation and Clemson University collaborated with Nigel Edwards, Fuels Assessment Section, in addressing the section relating to the use of tallow as a feedstock source for biodiesel production. A previous 141-page report was published in June 2006 that was commissioned in 2004 to study any animal or public health risks and environmental exposure issues that might result from using animal fats for biodiesel fuel, particularly those materials specified as higher risk for transmissible spongiform encephalopathy (TSE).1

The earlier report concluded, “Biodiesel produced from animals infected with TSE poses a negligible risk to human and animal health. This conclusion extends even to the use of specified risk material (SRM) as a source of tallow, based on experimental evidence showing that rendered tallow from BSE- [bovine spongiform encephalopathy] and scrapie-infected tissues do not transmit disease to inoculated healthy animals.” The report also concluded that an absolute zero-risk assessment could not be made and would be impossible to prove at that time.

The new report (Chapter 7, pages 163-167, “Tallow and Biodiesel Production”) summarizes the 2006 analysis in respect to sources of animal tissues, tallow production, purification of biodiesel, and combustion of tallowate, but addresses current scientific reports. The new report, along with the 2006 study and all previous drafts, was reviewed by Dr. Annel Greene, Steve Woodgate, and myself after consulting with representative renderers. The conclusions were quite specific for tallow that was below the 0.15 percent insoluble impurity content as based on the World Organization for Animal Health, or OIE, standard. The risk of a human contacting variant Creutzfeldt-Jakob disease (vCJD) following exposure to airborne BSE resulting from the combustion of SRM-derived tallow was calculated to range from 10-11.43 to 10-7.23, lower than the spontaneous rate of vCJD occurrence in humans at 10-6. Thus, 0.15 percent or less insoluble impurity tallow was considered as a negligible risk feedstock source for biodiesel production.

However, a second scenario conclusion was formed for tallow in which the insoluble content of the SRM-derived tallow exceeds 0.15 percent and contains BSE agents. It was stated that there is a lack of empirical information and data to establish a negligible risk of infection given the uncertainty that exists. The uncertainty is whether the temperature of compression ignition engines is high enough for a sufficient length of time to render BSE agents inactive. Though no reference to further research was made, the uncertainty will probably result in attempts to acquire extremely expensive, long-term research grants.

As reviewers, it was encouraged to reference the controls, regulations, and the compliance records that exist for regulating SRM material and the insoluble impurity components. The level of compliance associated with all BSE regulations has exceeded that of nearly all regulations ever developed. The rendering industry is to be applauded for its record and attention to compliance. The numerous programs employed by the global rendering industry, to include the code of practice, hazard analysis and critical control point, Safe Feed/Safe Food, restricted use animal protein, and others, are actively employed at nearly all rendering facilities. But all renderers know this! Isn’t it frustrating that the need to train and retrain the doubters is a never-ending process.

The report is available at For more information or to obtain additional copies, contact Publications, Health Canada, Ottawa, ON, Canada K1A 0K9, (613) 954-5995, e-mail


1 Biodiesel from Specified Risk Material Tallow: An Appraisal of TSE Risks and their Reduction. 2006. Ottawa, ON, Canada: Advanced Technologies and Fuels Canada, Inc.

August 2012 RENDER | back