The European Food Safety Authority (EFSA) Biohazards Panel was invited to assess the validity of the outcome of a quantitative risk assessment (QRA) of the residual BSE risk in gelatine extracted from bovine bones. If the outcome was considered valid, the previous SSC opinion " On the safety with regard to TSE risks of gelatine derived from ruminant bones and hides (adopted by the SSC at its meeting of March 6-7th, 2003)" should be reviewed and an opinion should be given on how to interpret the results of the calculation in order to make an estimation of the number of potential variant Creutzfeldt-Jakob disease (vCJD) cases (human) expected per year in a population. 1. The general conclusions of the previous SSC Opinion are supported by the QRA. This should not be surprising since both are made on the same assumptions and many of the parameters fed into the QRA model, at this first stage of its evolution at least, must be regarded as expert opinion rather than experimental and or epidemiological data. 2. The QRA has provided a worst case mean estimate for the human exposure due to gelatine made by the acid or alkali methods from a mixture of bones including skull (including brain) and vertebral column (including spinal cord) sourced from cattle from a GBR IV country with unreliable surveillance of 1.71 x 10(-6) Cattle Oral Infective Dose 50 (CoID50) units per person per week. This is equivalent to an annual exposure of 8.9 x 10(-5) CoID50 units per person but assumes ALL gelatine in a person's diet is extracted from bovine bones; a more realistic proportion was considered to be 0.02 -0.05 of the total intake. The mean exposure of the UK population through food over the BSE epidemic (1980 -2001) was previously estimated as 0.004 CoID50 units per person per year, and so, by comparison, the worst case exposure due to bone gelatine in food (included as a proportion of 0.05 of total gelatine intake) is two to three orders of magnitude (900 x) less. The heat/pressure method of extraction of gelatine from bovine bones will give an additional exposure reduction by a factor of 100. 3. Similarly, the effects of removing the skull (and brain) and most of the spinal cord (but including the vertebral column) OR simply removing both skull and vertebral column from the source bones prior to extraction of gelatine by the acid or alkali process were estimated to reduce risk by factors of 1.9 x 10(3) and 2.0 x 10(5), respectively, compared to the mean exposure of the UK population through food over the BSE epidemic. Since more realistic scenarios, such as sourcing cattle from GBR III countries with reliable surveillance, etc have human exposures ten to one hundred fold smaller than these worst cases, the exposures estimated by the QRA model, with its current inputs and assumptions (linear dose response at very low dose; product homogeneity; etc.) due to bone gelatine can be considered very small compared to the historical exposure in the diet of the UK population. 4. The SSC Opinion, 2003, specifically recommends for GBR II, GBR III and GBR IV countries, that in addition to appropriate sourcing of bones, and pending the outcome of this QRA, the skull and vertebrae from bovine animals older than 12 months should not be used in the production of gelatine. In this context, the QRA of residual BSE risk in bone derived gelatine provides no support for this recommendation as the relevant exposures are regarded as very small compared to the historical exposure due to meat and meat products in the diet of the UK population.
