Volume 6: Human Health, 1989-96
3.
Introduction of the ban on Specified Bovine Offal
Preparation of the SBO Regulations
Introduction
Division of responsibilities for developing the SBO Regulations between MAFF and DH and within MAFF
Choice of legislation
Contentious offal: introduction
Tripe and rennet
3.332 The intention of the SBO ban was to prevent human consumption of those parts of the cow that were likely to pose a significant risk of infectivity if BSE proved to be transmissible to humans. This section traces the processes that led to the determination of those tissues which were to be covered by the ban.
3.333 Experimental research on scrapie carried out by Dr William Hadlow to which we have referred earlier (see table at paragraph 3.200) had indicated that brain, spinal cord, spleen, thymus, tonsils and intestines were high-risk tissues and the intention from the outset was that these should be included in the list of types of SBO.
3.334 More generally, the lympho-reticular system had been demonstrated to be a source of significant infectivity. This raised a problem. There could be no question of including the entire system in the ban. The approach ultimately adopted was to include in the ban those tissues, other than muscle, in which lymph nodes (macroscopically visible as opposed to lymph nodules which are only visible under microscope) were prevalent. It was on this basis that intestine was to be included in the ban.
3.335 In this section we shall be concentrating on a number of issues which fell to be resolved. The first was whether lymphatic tissue was to be found in all or any of the four stomachs of the cow to an extent which rendered it appropriate to include them in the ban. This was of commercial significance, for edible tripe was produced from these tissues and one of the stomachs, the abomasum, was the source of rennet, which was used for making cheese.
3.336 A second issue was whether an exception could be made from any ban on intestines to exclude casings used for sausages and black and white pudding, on the ground that the processing of the casing would remove the lymphatic tissue.
3.337 A third issue was whether an exception could be made from the ban in respect of calves under 6 months of age. Having been born after the introduction of the ruminant feed ban they should not, in theory, have been at risk of infection - unless BSE was capable of vertical or horizontal transmission, questions which were unresolved.
3.338 A fourth issue was whether it was acceptable that the spinal column of cattle should be used for the extraction of mechanically recovered meat (MRM), having regard to the risk that this might be contaminated with residual nervous tissue.
3.339 These last two issues merit particular attention, for the decision that was reached in the case of each of them was reversed some five years later.
3.340 We shall also be considering steps taken in relation to the enforcement of the SBO ban.
Division of responsibilities for developing the SBO Regulations between MAFF and DH and within MAFF
3.341 MAFF and DH had joint responsibility for working on a range of health and food safety issues. 1 Sir Derek Andrews, the Permanent Secretary of MAFF, and Sir Christopher France (Permanent Secretary: 1987-88, DHSS;1988-92, DH), along with other senior officials including the CMO, met at least every six months to discuss and review any policy issues which concerned both Departments. 2 Furthermore, the Cabinet Secretary chaired a weekly meeting of all Permanent Secretaries where any particular issues of concern to Departments in general could be raised. Sir Derek described the interface between MAFF and DH as a 'mixture of formal and informal relationships'. 3
Veterinary staff were responsible for professional advice both on animal health issues and on public health issues relating to farm animals and meat or other animal products. On the latter they maintained close contact with medical colleagues in the Department of Health . . . Similarly, there was frequent contact between administrative staff in Animal Health Group and administrative staff in DHSS, as well as with colleagues in other parts of MAFF. 4
3.343 So far as the SBO Regulations were concerned, DH let MAFF take the lead in formulating the ambit of the Regulations and in the consultation process. This was natural as, although the object of the exercise was the protection of public health, the technical issues were essentially ones that called for veterinary expertise. Furthermore, the understanding of DH was that MAFF's reason for introducing the Regulations was reassurance rather than protection of the consumer.
3.344 The division of responsibilities for the safety of human food between DH and MAFF was reviewed during the second half of 1989 by a Working Group chaired by Mr Andrew Whetnall. We describe their conclusions in Chapter 4, where we also deal with hygiene standards in slaughterhouses and the responsibilities of different parts of government for meat hygiene enforcement.
3.345 Within the administrative side of MAFF the Animal Health Division (AHD) was concerned with the development and implementation of policy on animal diseases. The Meat Hygiene Division (MHD) was responsible for policy and legislation on hygiene and inspection in meat plants, for import and export requirements relating to meat and for welfare of animals at slaughter. 5 Both these Divisions were involved in the preparation of Regulations to give effect to the proposed SBO ban.
3.346 The AHD and the MHD (along with the Animal Welfare Division and the Animal Medicines Division) were all based at Tolworth. The heads of each Division reported to Mr Cruickshank who was based in Whitehall so that he could be close to Ministers and other senior officials.
3.347 In mid-1989, when it became clear that the Minister wanted to impose a ban on certain offals, Mr Lowson wrote to Mr Cruickshank concerned that the AHD did not have the necessary resources to 'give this project a priority that is no doubt attached to it.' 6 In response, Mr M J Griffiths (MHD, MAFF) agreed that his Division would deal with the Legal Department on the preparation of the Regulations. 7 This left the AHD responsible for advising on policy in regard to BSE.
3.348 Sir Derek Andrews saw this division of responsibility as a 'logical and efficient allocation of the work in the circumstances' particularly as the AHD already had expertise in making policy in relation to BSE, whilst MHD had experience in handling slaughterhouse legislation. 8
3.349 The reasons for adopting this approach were set out by Ms Bronwen Jones (MHD) who told us:
This arrangement was adopted because the Regulations were designed primarily as a precautionary measure to protect human health from any risk and not a disease control measure; because the protection of human health was effected in this instance by imposing requirements in abattoirs; and because they were modelled closely on existing regulations governing the treatment and disposal of unfit meat. MHD were responsible for those regulations and for policy generally on abattoir hygiene and practices as far as they relate to the protection of human health from risks through food. 9
3.350 Sir Derek Andrews stated that 'The evidence before the Inquiry indicates, therefore, that AHD and MHD worked closely together, pooling their expertise as would be normal in a government department with specialised units'. 10 The contemporary documents suggest that there was, at least initially, a degree of tension between the two Divisions as to the sharing of the burden of introducing the SBO Regulations.
3.351 On 6 July Mr Griffiths minuted Mr John Maslin (Senior Executive Officer, Animal Health Group, 1985-96, MAFF) 11 confirming the division of responsibilities between AHD and MHD. He stated:
The only point I wish to make now is that I must ask that Mr Duncan Fry is not shown in the letter as the contact point for comments.
We did agree, as Mr Fry has considerable experience of the legislation, that he would assist this work, by acting as your Division's agent in the preparation of the draft SI. Indeed, he then gave the best part of his time, which meant many late nights in the office, to the job in the two weeks before he went on leave. My agreement to these arrangements was on the clear understanding that consultation would be undertaken by AH Division. When comments are in, we will be prepared, as now, to continue to give as much help as possible. 12
3.352 The reaction of officials in AHD can be confirmed from manuscript endorsements on this minute which were not intended to be preserved for posterity. These indicated that they were less than happy with their allotted roles.
3.353 Both veterinarians and administrators were involved in preparation of the regulations. Mr Cruickshank stated that:
The division of responsibilities between the veterinary and administrative staff was never very precisely defined. 13
Veterinary and administrative staff worked in separate hierarchies but in very close partnership. 14
3.355 On 7 June 1989, Mr Lawrence minuted Mr Griffiths about the meeting that Mr Cruickshank had had with the Minister the previous evening, discussed in paragraph 3.245. In relation to the legislation to be used under which to bring the ban:
It was agreed, if it is legally possible to do so, that it would be best to condemn offals at source rather than seek to prohibit their use through a further amendment to the Meat Products Regulations. 15
3.356 Mr Fry minuted Mr Lawrence on 8 June stating that it would be possible to regulate to prohibit the use of certain types of offal in human food under sections 4 and 13 of the Food Act 1984. He advised that the Regulations would probably have to stand alone, rather than be an amendment to the existing Meat Inspection Regulations as:
we are not able to define the material as unfit for human consumption nor attribute any health hazard to it. The enforcement authority will be local authorities - whose staff enforce the legislation in slaughterhouses. 16
3.357 Mr Fry noted that lawyers still needed to consider the final details, but he hoped the material to be banned 'could be brought within the controls of the Meat (Sterilisation and Staining) Regulations for its subsequent treatment'. Using the Food Act as the vehicle for making the Regulations would also require Ministers to 'consult with such organisations as appear to them to be representative of interests substantially affected by the Regulations or by the Order'. 17
3.358 In his letter to Mr Clark on 9 June 1989 about the SBO ban proposal, Mr MacGregor had said that he was 'anxious to introduce the necessary Regulation, which will be made under the Food Act, with the minimum of delay'. 18 As Mrs Attridge stated in oral evidence:
The Animal Health Act is a very directly applying Act. Its powers can be made that day and come into force that day. Therefore, if one can use the Animal Health Act, one can make immediate regulations, but clearly this could not be under the Animal Health Act because it was not relating to animal diseases. It was a recommendation that related to foodstuffs, so by circular argument, when one looked further into it, one got back to the Food Act 1984. 19
3.359 On 15 June 1989, Mr Fry sent a draft minute instructing lawyers to prepare the proposed Regulation to Mr Lawrence, Mrs Attridge, Mr Crawford and Mr L Gunatilleke (Legal Department, MAFF) and others. He explained in a covering note that 'I have gone for treatment along the lines of that required in the Meat (Sterilisation and Staining) Regulations for specified offal.' 20 Mr Fry said in his statement to the Inquiry that he had frequent discussions with Mr Guntatilleke to establish the legal details of the Regulations. 21 Mr Fry also sent a minute to Mr Cruickshank (to be sent to Mr Barry Atwood of the MAFF Legal Department if Mr Cruickshank wished) 'pressing for amendments to existing SIs and outlining how they might work' rather than having separate Regulations as was being envisaged. 22
3.360 However, five days later the form of the legislation was still to be clarified. Mr Fry informed his colleagues that:
The lawyers favour a stand alone SI banning sale etc backed up by a requirement to treat this material in the same way as specified offal in the Meat (Sterilisation and Staining) Regulations . . . The alternative approach is to further consider a provision in the Meat Inspection Regulations and the Fresh Meat Export (Hygiene and Inspection) Regulations along the lines of Schedule 2 para 1(2) and Schedule 8, Part VIII para 1(2) respectively which deal with certain meat being regarded as unfit for human consumption. 23
3.361 Mr David Taylor (Veterinary Head of Section of the Red Meat Hygiene Section MAFF, May 1987-April 1997) responded to Mr Fry on 22 June 1989. He stated that he preferred amending the Meat (Sterilisation and Staining) Regulations because the relevant schedules in the other Regulations required the inspector to make a judgement as to fitness, when no such judgement would be required for SBO. Further, the Meat (Sterilisation and Staining) Regulations already provided for the treatment and handling of unfit offal. 24
3.362 After the Regulations had been drafted and a proposed consultation document was submitted to the Minister on 7 July 1989, Mr Cruickshank said that 'we have tried wherever possible to stick to the procedures for handling unfit meat in the Meat (Sterilisation and Staining) Regulations, with which the industry is familiar'. He noted that in some cases that had not been possible, but workable arrangements had been devised. 25
Contentious offal: introduction
3.363 As indicated in the introduction to this section, the aim of the SBO ban was to prevent high-risk offal entering the human food chain. Although brain, spinal cord, tonsils, spleen, thymus and intestines had been identified as high-risk offal to be included in the ban, there were a number of additional issues to be resolved in relation to the proposed ban. In particular whether:
- to include tripes and rennet in the ban;
- to include mesenteric fat in the ban;
- to exclude casings from the ban on intestines;
- to exclude calves under 6 months of age from the ban;
- it was acceptable to use spinal column of cattle for the production of MRM; and
- the status of brain as an SBO would compromise the use of bovine heads for meat recovery.
3.364 Research and discussion proceeded on all of these topics simultaneously between early June and mid November 1989, when the Regulations were finalised and came into effect. In this section we trace the development of policy on these topics, including the additional work by Mr Bradley in this area, the consideration of the responses to the public consultation on the proposed ban and the views of independent experts.
3.365 As a result of our separate coverage of each of these topics, many of the events, including the various meetings held by Ministers and/or officials during this period, appear several times. In order to reduce some of the repetition associated with this detailed coverage of policy development, we first provide a brief outline of the main stages and events in the process. We have already mentioned some of these events, particularly those in June, earlier in this chapter.
6 June: Mr MacGregor meets senior MAFF officials
3.366 The meeting with Mr MacGregor was attended by Mr Andrews, Mr Cockbill, Mr Meldrum, Mr Cruickshank, Mr Lawrence, Mr Gueterbock and Mr Coe from MAFF and by Dr Metters from DH.
3.367 The purpose of this meeting was to discuss the issues raised in Mr Cockbill's submission of 2 June on various aspects of the proposed offal ban and Mr Thompson's note of 2 June on various policy options on BSE. Its purpose was also to 'clear the ground and decide on the main lines of action prior to the meeting with Sir Richard Southwood the following day'. 26
7 June: Mr MacGregor and senior officials meet Sir Richard Southwood
3.368 The meeting between Mr MacGregor and Sir Richard Southwood was also attended by Mr Cruickshank, Mr Meldrum, Mr Coe and Mrs Attridge from MAFF, and by Dr Metters and Dr Pickles from DH.
3.369 The meeting discussed the background to the proposed ban of specified offal, including the possible exemptions of casings and calves. 27
13 June: press announcement of the proposed SBO ban
3.370 DH and MAFF issued a joint press release to announce their intention to impose a ban on the sale of SBO for human consumption. 28
15 June: Mr Fry circulates draft instructions to lawyers on the Regulations
3.371 Mr Fry sought comments from others in MAFF on his draft instructions to lawyers on the preparation of the Regulations to implement the specified offal ban. The draft instructions provided for, among other things, the exemptions on casings and of calves of less than 6 months of age. They also explained how the Regulations should deal with the removal of bovine brains from skulls. 29
19 June-21 July: Mr Bradley's reports
3.372 Policy decisions on what should be included in the SBO ban were largely based on the work undertaken by Mr Bradley during this period. He carried out a series of studies to determine the extent to which lymphatic tissue was present in the digestive system of cattle. 30 The results of these studies were presented to Mr Meldrum, Dr Watson, Mr Kevin Taylor, Mr Wilesmith, Mr Lawrence and Dr Woolfe in a series of ten reports. 31
3.373 While Mr Bradley was conducting his studies, MAFF continued the process of formulating policy on the content of the SBO ban.
27 June: first meeting between MAFF officials and representatives of relevant industries
3.374 This meeting was attended by representatives of the tripe manufacturing, and pet food industries, the MLC and the United Kingdom Renderers Association (UKRA). MAFF was represented by Mr Meldrum, Mr Lawrence and Mr Maslin.
3.375 The meeting discussed the background to the SBO ban, and Mr Bradley's studies. Also covered was the question of communication with the industry and the estimated size and value of the tripe industry. 32
7 July: submission of draft regulations and consultation letter to Mr MacGregor
3.376 Mr Cruickshank sent a submission incorporating a proposal for regulations and a consultation letter to Mr MacGregor. His covering note commented that MAFF had been in close contact with DH in drawing up the consultation document. At this stage the ban included brain, spinal cord, spleen, thymus, tonsils, intestines and stomachs (rumen, reticulum, omasum and abomasum). Exempt from the ban was the spinal cord of animals of less than 6 months of age where the carcass had not been split after slaughter, the small intestine used in the manufacture of sausage casings, and rennet deriving from calves under 6 months. 33
19 July: submission of revised consultation letter to Mr Donald Thompson
3.377 Mr Cruickshank submitted a revised consultation letter to Mr Thompson. The covering note updated the Minister about recent advice from CVL which added further weight to the view that bovine stomachs, from which tripes and rennet were prepared, need not be included in the ban, and that the large intestine as well as the small intestine would be similarly exempt. 34
21 July: DH agreement to the proposals in MAFF's consultation letter
3.378 Dr Pickles forwarded MAFF's revised consultation letter to Sir Donald Acheson and Dr Metters, indicating that she was content with the proposals for the ban on specified offal. 35
Ministerial changes in late July
3.379 On 24 July 1989 Mr Gummer succeeded Mr MacGregor as Minister of Agriculture, Fisheries and Food. The following day he was joined by Messrs David Maclean and David Curry, who succeeded Messrs Donald Thompson and Richard Ryder as Parliamentary Under Secretaries (Commons).
26 July: MAFF issues the consultation letter on the proposed SBO ban
3.380 On 26 July, following Mr Thompson's approval, Mr Lawrence sent out the consultation letter to a large number of industry and other groups, including the meat industry, food retailers and manufacturers, farmers, local authorities, scientific institutions and the European Commission. The letter sought their views about the proposal for a ban on the sale of certain types of bovine offal and asked for a response by 13 September. The letter noted that the BSE agent might be present in the brain, spinal cord, spleen, thymus, tonsils and intestines. 36 Responses were widely circulated within MAFF by Mr Maslin 37 and also sent to Dr Pickles at DH and officials in the Agriculture departments in Scotland, Wales and Northern Ireland.
18 September: the ad hoc meeting of experts
3.381 This meeting was attended by Sir Richard Southwood, Dr Tyrrell, Dr Kimberlin, Mr Meldrum, Mr Bradley, Mr Lowson, Mr Lawrence, Dr Metters and Dr Pickles.
3.382 The meeting had been proposed by Dr Metters on 7 August with the aim of seeking appropriate scientific advice on maternal transmission, particularly in relation to the proposal to exclude calves under 6 months from the ban.
3.383 In addition to the possible exemption for calves, the meeting also discussed the issues of abomasum, rennet and casings. 38
27 September: meeting to discuss responses to the consultation letter
3.384 This meeting was chaired by Mr Cruickshank and attended by Mr K Taylor, Mr D Taylor, Mr Lowson, Mr Lawrence, Mr Maslin, Mr Fry and others from MAFF, Dr Wilesmith from CVL, Mr Anderson (Department of Agriculture and Fisheries for Scotland), Mr Graham Podmore (Welsh Office Agricultural Department) and Mr R Martin (Department of Agriculture for Northern Ireland). 39 No representative from DH was present at the meeting. Dr Pickles had been invited at short notice but was unable to attend. 40
3.385 On 29 September, Mr Maslin circulated a note of the meeting to all the attendees and to Mr Meldrum, Mr Keith Baker (Assistant CVO, Meat Hygiene Division June 1988-March 1996) and Mr Bradley (among others). 41 Dr Pickles and Dr Metters were sent copies of the meeting note on 3 October. 42
19 October: Mr Meldrum writes to Dr Jeremy Metters
3.386 Mr Meldrum's letter of 19 October to Dr Metters set out the latest rationale for the proposed policies on rennet, casings, mesenteric fat and calves, and enclosed 'further detailed advice' from Dr Kimberlin. He also sought a meeting with Dr Metters to 'discuss the way forward'. 43
3.387 A few days later Mr Meldrum copied this letter to Dr Tyrrell and Sir Richard Southwood, seeking their comments 'on the approach we are advocating and which we hope to present to Ministers'. 44 Both Dr Tyrrell and Sir Richard subsequently endorsed the proposed approach.
20 October: the meeting with the Meat Industry Liaison Group (MILG)
3.388 Mr Lowson, Mr Lawrence, Mr Maslin, Mr Baker and others from MAFF attended this meeting. The purpose of the meeting was to discuss a number of concerns raised by the MILG in their response to MAFF's consultation on the proposals to ban certain types of SBO. 45
30 October: DH recommends MAFF to proceed as it thinks fit with the proposals
3.389 Dr Metters responded to Mr Meldrum's letter of 19 October, and advised that he agreed generally with the proposals as they now stood and that he was content for MAFF to proceed. 46
2 November: circulation of the final draft regulations to MAFF Ministers
3.390 Mr Lawrence distributed a final draft of the Regulations with a submission to MAFF Ministers. This proposed that the four bovine stomachs, mesenteric fat (used for tallow and edible fats), MRM and offal from calves under 6 months old should be exempt from the ban. However it recommended that casings should not continue to be available, as an ultra-precautionary measure. 47
7 November: Ministers meet to discuss Mr Lawrence's submission
3.391 The meeting was attended by Mr Gummer, Mr Maclean, Mr Andrews, Mr Packer, Mr Meldrum, Mr Cruickshank, Mr Lawrence, Mr Dugdale and Mr Gueterbock. 48
3.392 The Ministers agreed the ban as set out in submission of 2 November. They were told that lawyers envisaged two weeks to make the necessary amendments to the draft orders. Mr Gummer replied that he wished this process to be speeded up and would like the ban to come into force the next day, if at all possible. 49 His statement to the Inquiry explained that this was to reassure the public that action was being taken. 50
3.393 Industry representatives were telephoned and told about the inclusion of sausage casings. 51
3.394 Dr Pickles sent the submission on the proposed regulations to DH Ministers, recommending that they co-sign.
3.395 Mr Cruickshank telephoned Mr Peter Davis, head of MAFF's legal branch A1 to inform him of the Minister's request that the Regulations should be ready for signature that day. Mr Davis concluded that a minimum of 48 hours would be needed. When that was initially regarded as too long by the Minister's office, the head of MAFF's legal department sought an appointment with the Law Officers. Involvement of the Law Officers became unnecessary when the Minister's office agreed to accept 48 hours.
8 November: signature of the Regulations
3.396 At around 8.15pm on 8 November 1989 Mr Davis forwarded a keyed copy of the Regulations. 52 They were submitted by Miss Jones for signature later that evening. Her covering minute noted that copies of the Regulations would be circulated to Chief Executives of District Councils in England and Wales, who were the enforcement authorities. 53 The Regulations were made on 8 November, laid before Parliament on 9 November and came into force on 13 November 1989. 54
3.397 We now deal with each of the contentious offal types in turn, explaining how the policy on each was developed.
The CMO raises the issue of whether tripe should be added to the list of types of banned offal
3.398 The day before the announcement and press briefing on the proposed offal ban, Mr MacGregor met the CMO who sought clarification about whether bovine tripe would be included in the ban. Mrs Stagg's minute describing the meeting recorded that Mr MacGregor agreed to examine the question of bovine tripe and it requested a note from Mr Cruickshank on this point for the press briefing the next day. 55
3.399 On 13 June, Mr Cruickshank reported to Mr MacGregor:
I understand from Mr Crawford that tripes are made from the stomach of the animal. They have not previously been mentioned in this connection, but the veterinary advice is that they will contain significant quantities of lymphatic tissue. Like intestines, they are scraped in the course of preparation, but they are not scraped as thoroughly as intestines. There is therefore likely to be more lymphatic tissue left on the material. Although in the time available it has not been possible to establish to what extent the scrapie agent has been found in sheep stomachs, it would seem likely from first principles that the stomachs of infected animals would be affected.
Unlike the other offals which we are proposing to prohibit, I understand there is some economic interest in tripes. I believe for example, that Northern Ireland exports significant quantities of tripes to the Far East.
As it has not been possible in the time available to give this issue as full consideration as it might warrant, I would suggest that we leave the announcement unchanged, but in the consultation document which is being prepared we might air the possibility of adding stomachs to the list of offals to be rejected. 56
3.400 Accordingly, the announcement on 13 June did not mention tripe or whether it would be included in the offal ban. 57
Mr Lawrence clarifies MAFF's 'line to take' on tripe
3.401 Following the 13 June announcement, MAFF were inundated with telephone calls seeking clarification on their intentions in relation to the ban. 58 On 15 June, Mr Lawrence minuted Mr Cruickshank, Mr Meldrum, Mr Bradley and others in MAFF, to pass on some of the points raised. On tripe, he noted:
. . . the line we are taking is to say that, whilst it is not specifically included in the list of offals which the Ministry wishes to ban, careful consideration is being given to its possible inclusion after taking the best possible scientific advice. I have already had a useful discussion with Mr Bradley on this. He informs me that three of the four stomachs may be used for tripe: these are the rumen, reticulum and the omasum. The abomasum is not used. The oesophagus is apparently part of what is described as tripe and can also be used for human consumption. Urgent consideration, therefore, needs to be given to the amount of lymphatic tissue in the three stomachs, and presumably the oesophagus, to see whether it presents a risk after preparation. 59
3.402 The statement that the abomasum was not used proved to be incorrect. It was the source of a variety of tripe known as 'black tripe' (see paragraph 3.408). Abomasum had a further significance as a source of rennet, which was extracted from calf abomasums for the production of cheese.
Mr David Taylor's advice on tripe
3.403 On 16 June, Mr Fry of MAFF's MHD reported to Mr Cruickshank that it was not the practice to scrape the stomach in the manufacture of tripe, and that in any event, scraping would not ensure removal of substantial amounts of lymphoid tissue. This information had come from Mr David Taylor. 60
Mr Bradley's investigations into the distribution of lymphoid tissue in the digestive system of cattle
3.404 The first two of Mr Bradley's reports (on 19 and 22 June 1989) presented results from examination of bovine tissue samples stored at CVL. 61 These initial results showed that there were significantly fewer lymphoid nodules in the oesophagus and tripe organs-rumen, reticulum, omasum-than in the abomasum and the other parts of the digestive tract. Mr Bradley concluded that tripe and oesophagus might therefore present a lower risk of harbouring the BSE agent. However, he cautioned that the tissues he had examined were from diseased cattle and might be unrepresentative of the true picture. He reminded his readers that a more detailed study on the digestive tract of an adult beef animal reared for human consumption was shortly to be under way.
3.405 Mr Bradley's third report of 2 July, presented the results from his examination of the digestive system of an adult beef animal. This study largely confirmed his previous observations on the distribution of lymphoid tissue. He observed that dressing of the tripe might remove the small traces of lymphoid cells. Further:
Even if it did not, the risk factor for grey tripe organs (ie, rumen, reticulum and omasum) and oesophagus in regard to BSE infectivity is, assuming a correlation between presence of lymphoid tissue and BSE infectivity, much lower than for unprepared abomasum and particularly small intestine and parts of the large intestine. The true risk factor can only be established by infectivity studies but the present study suggests that grey tripe organs and oesophagus are of acceptably low risk for human consumption provided these results pertain with a large selection of animals. 62
3.406 Mr Bradley's fourth report of 5 July presented the results from his examination of tripe specimens collected from a visit to the premises of a bovine tripe dresser on 28 June. 63 The specimens were collected at the point of receipt from the abattoir, after each of the three main processing procedures and at the final product stage. Mr Bradley reported that the fresh untreated rumen and reticulum had precisely similar structure to that seen in a freshly killed beef animal; further, that although the processing stages removed certain layers of tissue from the rumen and reticulum, the lymphatic nodes were not removed but they were nevertheless minimal. He concluded that the risk factors for BSE infectivity of grey tripe organs and the oesophagus were much lower than for unprepared abomasum and intestine.
3.407 In his fifth report of 12 July, Mr Bradley presented the results from his further examination of the tripe specimens collected on 28 June, in particular the immunological activity of the lymph nodules in the digestive tract. 64 The results further supported the conclusions from his previous reports that the potential for BSE infectivity would be a lower risk in the grey tripe than in the abomasum or small and large intestines.
3.408 In his sixth report of 13 July, Mr Bradley presented the results from his examination of five beef cattle slaughtered for human consumption. The results were consistent with his previous observations: the abomasum contained many more lymph nodules than in the oesophagus or in the rumen, reticulum or omasum. He concluded that:
. . . abomasum should be regarded as a higher risk tissue in regard to the potential for BSE infectivity. Note however that if the mucous membrane was entirely removed during the processing to black tripe for human consumption this risk would be reduced or eliminated. 65
3.409 Mr Bradley also submitted his seventh report on 13 July, which summarised the results of his studies on the risks of infectivity of tissues from the bovine digestive tract. He noted:
The spectrum of perceived risk for BSE infectivity for man from consumption of infected animals is infinite ie there is none at one end or 'all cattle exposed to infection should be killed and incinerated' - (Dr Grant). The Government has seen fit to 'set the standard' somewhere between the extremes and closer to the first. At present the 'needle' setting the standard is on the move from the point of no risk to the point of increased risk. It is therefore important to establish at least one and possibly several 'stops'. The present tripe problem provides an opportunity to set such a stop as well as to protect an important and safe industry. It is therefore paramount that the detailed scientific study of fresh and cooked tripe morphology is soundly based, agreed with experts in the field, understood by administrators and politicians and presented honestly and effectively to the public and media (if required). 66
3.410 Mr Bradley's conclusions and recommendations were:
Based on the studies conducted and on the assumptions made which have been discussed with other experts in the field, it is recommended that as an interim measure and until the results of infectivity experiments are known oesophagus (weasand), reticulum, rumen and omasum are continued to be permitted for sale for human consumption provided the procedural changes in preparation of tripe mentioned here and in previous reports are adopted. [These have been omitted from this summary.]
Infectivity studies in mice should be initiated and paid for in part at least by the industry.
Untreated abomasum and intestine should not be used for human consumption.
Studies on the preparations of rennet and gut casings from cattle and histological and other studies as required should be initiated to determine their safety in regard BSE infectivity.
Cross-contamination of 'clean' by 'dirty' tissues should be avoided in all processes. 67
3.411 This was followed on 14 July by Mr Bradley's eighth report, a pictorial account of lymphoid tissue in the bovine digestive system. 68 This was complementary to his previous reports and illustrated the various tissue sections he had examined. He concluded:
The abomasum, small and large intestine should not be available for human consumption unless all the parts containing lymphoid tissue are completely removed. 69
3.412 His ninth report of 18 July was on the immunological activity of lymph nodules in the digestive tract from mature beef cattle slaughtered for human consumption. 70 The results supported the findings from his previous studies that oesophagus and grey tripe presented a lower risk for BSE infectivity than abomasum or intestine.
3.413 Mr Bradley's tenth report of 21 July focused on the abomasum from adult beef cattle. 71 In particular the study investigated whether the lining of the abomasum, and its component lymphoid tissue, was removed or destroyed by tripe dressing and processing. The results showed that there was little change to the thickness of the abomasal wall during dressing and processing, and Mr Bradley concluded that:
Substantial quantities of lymphoid tissue remain in the product at the point of sale. 72
3.414 Mr Meldrum wrote to Mr Bradley on 21 July advising that he did not wish to initiate any further investigations into the production of rennet 'since Ministers are being advised to exempt abomasums from the "offal ban" and I have no wish to stir up any more hornets nests!'. 73
27 June: first meeting between MAFF officials and representatives of relevant industries
3.415 The note of this meeting records that Mr Meldrum explained the background to the proposed SBO ban, the concern about lymphatic tissue in tripe, and that a decision would be taken after the findings from Mr Bradley's scientific studies on tripe were known.
3.416 The tripe industry representatives discussed their concerns about the proposed ban. In particular one representative asked what the difference was between residual lymphatic tissue in meat (on which no action was to be taken) and tripe. The note records that Mr Meldrum explained that:
. . . it was all on assessment of risk and a line had to be drawn somewhere. It was impractical to remove lymph nodes in meat from carcasses at the slaughterhouse but that butchers removed these from meat before sale. 74
3.417 The possible consequences of banning tripe were discussed in the context of the size and value of the tripe industry. One example given at the meeting showed that at one abattoir sales of tripe and omasum were £300,000 to £350,000 per year from processing 1,400 animals per week. 75
Mr Meldrum's contribution to the development of the 'line to take'
3.418 Also on 27 June Mr Meldrum minuted Mr Maslin providing a contribution for a submission to Mr MacGregor about the consultation letter on the proposed ban on the use of SBO. The minute was copied to Mr Bradley and others in MAFF. On the issue of tripe, Mr Meldrum wrote:
As the Minister will be aware, banning the use of tripes (stomachs) is not only contentious but technically weak. According to the literature the agent is not present in tripes although it is present in the intestines. However, tripe may contain some lymphoid tissue where the agent may be present. We are carrying out some work, urgently, at the Central Veterinary Laboratory into the structure of tripe and, in particular, to determine whether any lymphoid tissue is present in treated tripe. In the meantime we propose to consult on the basis of a ban on the use of tripe and can take a final view when the consultation process is complete and we have finished our investigations at the CVL. However by so doing we are casting doubt on the safety of tripe but the consultation letter is worded so as to put the issue in perspective without alarming the public unduly. 76
3.419 Mr Meldrum's conclusions on rennet were the following:
This is produced from calf abomasums by a system of separation of mucus, filtration and exposure to a pH between 2 and 3 for about 2.5 hours. This will not destroy the agent but is likely to reduce the level of the agent in the final product. We therefore conclude that the risk from such rennet is very small indeed and may be totally absent since the agent is unlikely to be in the abomasum in the first place . . . The consultation letter, therefore, makes no reference to a ban on rennet for the reasons described above. 77
3.420 A week later Mr Bradley replied to Mr Meldrum's minute. On the subject of tripe he reminded Mr Meldrum that:
There have been no studies I know of to determine the infectivity of bovine tripe, therefore, we do not know if it is infected or not. This applies also to sheep. 78
3.421 With respect to rennet Mr Bradley stated:
Whilst I appreciate that rennet is an important commodity and should be cleared if it is scientifically possible to do so, I urge a degree of caution for the following reasons:-
a) If BSE transmits maternally the absence of exposure to scrapie or BSE-contaminated meat and bone meal alone is not an argument to defend the use of rennet since all material swallowed (including amniotic fluid in utero) passes into the abomasum. Maternal transmission might therefore expose the calf and abomasum to infection.
b) The abomasum of calves contains lymphoid nodules in the thickness of the wall. The full extent of this has not yet been examined in the calf but in a 2 year old ox killed for human consumption lymphoid nodules are extensive.
Despite these findings and even assuming oral (and thus abomasal) exposure to the unconventional agent it may be possible to "clear" rennet scientifically if all the cellular and membranous material is removed in processing. Even this may need some further informed opinion from NPU or Dr Kimberlin. 79
7 July: submission of draft regulations and consultation letter to Mr MacGregor
3.422 Mr Cruickshank's submission of 7 July to Mr MacGregor commented that work on the submission had proved more difficult and time-consuming than expected for two reasons:
First, there is the Chief Medical Officer's last-minute suggestion that tripes should be included in the ban. Tripes, unlike the other material which we proposed banning are of economic significance to the industry. It is unclear to what extent prepared tripes contain lymphatic tissue which could harbour the BSE agent. Work is being done urgently at the CVL to establish the position, but the results will not be available for another week or two. Rather than hold up the consultation further, it seems best to issue the document with a clear indication that we shall only ban tripes if the investigations reveal there could be a risk.
Secondly, our legal advice is that the consultation document must specify very precisely what we intend to put in the regulations. This has meant that we have had to consider in great detail the procedures to be applied in slaughterhouses in handling the various types of material involved, and the procedures for movement of this material on leaving the abattoir. We have tried wherever possible to stick to the procedures for handling unfit meat in the Meat (Sterilisation and Staining) Regulations, with which the industry is familiar. In some cases this has not been possible, but we have been able to devise arrangements which will I believe be workable. 80
3.423 The draft consultation letter attached to Mr Cruickshank's note explained that the abomasum of animals not more than 6 months old and used in the manufacture of rennet, would be exempted from the scope of the Regulations. 81
3.424 On 14 July, Miss Bowles (Private Secretary to Mr Thompson) minuted Mr Cruickshank in response to his submission of 7 July, advising him that Mr Thompson would be handling the policy on SBO. The minute noted Mr Thompson's request for the consultation document to be amended to say that scientific evidence had not established any need for tripe to be included in the ban. It also noted that Mr Thompson was content for tripe to be made the subject of separate regulations and consultation, if it proved necessary to ban it at a later date. 82
Mr Meldrum reviews the 'line to take' on tripe in the consultation document
3.425 Mr Meldrum minuted Mr Crawford on 17 July commenting on Mr Bradley's work and recommendations up to 14 July. In relation to tripe and rennet his minute stated:
It is clear from Mr Bradley's reports that oesophagus, rumen, reticulum and omasum can be used for human consumption without restriction. The small and large intestines should only be used as casings.
Mr Bradley has demonstrated that the abomasum contains a similar amount of lymphoid tissue to the intestines. However, in the preparation of black tripe the mucosa is likely to be removed and for that reason abomasum should not present a human health hazard when used either as black tripe or casings.
I have already covered the production of rennet in an earlier minute and I have no wish to change the view expressed at that time and reflected in the submission to the Minister. Mr Bradley has commented that calves derived from BSE affected dams are higher risk from the rennet production viewpoint. However, bearing in mind that by the time the calf is killed any material derived from its dam at birth will have been passed and that the agent will be at a very low level indeed if at all in its carcass, such an animal would be a very low risk indeed. This taken with the effect of the pH in rennet production (to which I have suitable references from Mr D M Taylor at NPU, Edinburgh) should ensure that the rennet produced does not present a human health hazard . . .
The consultation letter can therefore be recast along the lines I have indicated above. It therefore follows that both small and large intestines with the exception of casings would not be permitted for human consumption but that no action would need to be taken with any of the four stomachs on the basis that we are totally content with rumen, reticulum and omasum and that the products of the abomasum are prepared in such as way as to be a negligible human health hazard. 83
3.426 Mr Meldrum asked Mr Crawford to consult with Mr Cruickshank on amending the consultation proposals, as described, and to clear the 'line to take' with Dr Metters, Deputy CMO. 84
Involvement of DH in preparation of the consultation document
3.427 MAFF had consulted DH on the draft consultation document early in July. Dr Pickles had written to Mr Maslin on 7 July setting out her reservations about the draft, without commenting on the proposed policy on tripe or rennet. 85
3.428 On 17 July 1989, Dr Pickles minuted the CMO about MAFF's plans not to ban tripe, as proposed by Mr Meldrum. She advised that she had agreed to a change in the draft consultation letter that may appear to 'contradict what CMO had agreed earlier'. She noted that originally DH, at the suggestion of the CMO, had asked for tripe to be banned, believing it to be small intestine which possibly contained lymphoid tissue (see paragraph 3.399). She said that she had now been informed that tripe was from the higher parts of the bovine digestive tract and did not contain lymphoid tissue. She commented that Dr Kimberlin was content that it presented no risk. 86
3.429 Dr Metters was contacted on 18 July by MAFF about Mr Bradley's results and the revised 'line to take' on tripe. The next day he minuted Dr Pickles 87 noting that, in addition to their work on sausage casings:
The CVL had also investigated the lymphoid content of bovine stomachs, particularly the abomasum. This was in relation to the sale of bovine stomachs as tripe, which apparently is sold in 'white' or more rarely 'black' varieties. Here again the laboratory had found that the lymphoid content of tripe as presented for human consumption was minimal. Their conclusion is that tripe should not be included as one of the banned bovine offals.
MAFF wished to inform us of their histological findings and conclusions. As a result of these they intend to state in the forthcoming consultation letter that bovine stomach, in the form of tripe and stripped intestine, used for sausage skins, will both be exempted from the ban of other 'Southwood' offals. 88
3.430 Dr Metters recorded that 'If MAFF were satisfied with the findings from CVL, DH would certainly not wish to second-guess their findings.' However, Dr Metters noted that those who disagreed would have an opportunity to state their case to MAFF during the consultation period.
19 July: submission of revised consultation letter to Mr Donald Thompson
3.431 On the subject of tripe, the revised covering letter enclosing the consultation letter sent by Mr Cruickshank to Mr Thompson noted that Ministers had not wished to include tripe in the offal ban, and:
In fact we have now received advice from CVL that bovine stomachs, from which tripes are prepared, need not be included in the prohibition. Similarly, the procedures used in the production of rennet from the fourth stomach (the abomasum) are such that rennet production need not be restricted. 89
26 July: MAFF issues consultation document on the proposed specified offal ban
3.432 The consultation document did not contain any references to, or explanations of proposed exemptions of tripe, abomasum and rennet from the ban.
Correspondence between Mr Meldrum and Dr Jeremy Metters on the reasoning behind the exemptions for tripe and rennet
3.433 On 24 July, two days before the consultation document was issued, Mr Meldrum had written to Dr Metters confirming the reasoning behind the exemption from the SBO ban of stomachs and of intestines for casings. 90 Mr Meldrum was writing at the request of Dr Pickles who had advised the CMO on 21 July that she was content with the consultation proposals. 91 Mr Meldrum reported on the conclusions from the CVL work to establish the possible presence of lymphoid tissue, possibly harbouring the BSE agent, in the proposed types of offal. On tripe and rennet, Mr Meldrum explained:
The results show that, with the exception of the abomasum, the amount of lymphatic tissue present in the stomachs is significantly lower than is found in lung and is virtually constantly absent in the oesophagus . . . Consequently such tissue in stomachs should present a minimal risk. We are also satisfied from our investigations into the processing of tripe that the associated lymph nodes are removed by dressing.
The abomasum has similar levels of lymphatic tissue to the intestines. However, in the preparation of tripe from this stomach the associated lymph nodes are removed and the mechanical preparation will remove some of the mucosa. However, although the majority of the lymphatic tissue in the mucosa is retained after preparation any infectivity would be significantly reduced by the heat treatment to which the material is subjected. For these reasons the abomasum should not present a significant human health hazard when used as tripe.
Rennet is produced from bovine abomasums by a system of separation of mucus, filtration and exposure to a pH between 2 and 3 for about 2.5 hours. Though this will not destroy all the agent present the pH treatment will significantly reduce the level in the final product should it be there in the raw material. I believe that any risk from rennet is therefore negligible.
3.434 On 3 August, Dr Metters responded to Mr Meldrum's letter. 92 He was satisfied with Mr Meldrum's conclusion that tripe made from the three bovine stomachs (rumen, reticulum and omasum) should present only a minimal risk. He considered, however, that abomasum presented:
a more difficult decision as the lymphatic and lymph node distribution is more similar to the rest of the intestine than the other three stomachs. Furthermore unlike the intestines, after processing and preparation the majority of the lymphatic tissue in the mucosa remains. Thus any infectivity that there may be present in the lymphatic tissue will only be reduced by the heat treatment. The next question then posed is the extent to which heat treatment to which the abomasum tripe is subjected, is likely to reduce any infectivity that may possibly be present and hence any risk to human health. As I am not familiar with the temperature levels used to treat abomasum tripe I am in no position to comment. However, I would make the point that the transmissible agent in Creutzfeldt-Jakob Disease is renowned for its resistance to heat. 93
3.435 Dr Metters noted that further studies, as recommended in the Tyrrell Report just published in June 1989, would be needed and would take time. He concluded that 'in the interim we are not aware of any data that would conflict with the conclusions you have reached regarding the possible risk to human health.' 94
3.436 On the issue of rennet, Dr Metters referred to a telephone call with Mr Meldrum where the latter had advised that further data had been received on rennet from the NPU. He said that DH did not have access to these data, but had no reason to disagree with the advice MAFF had received. 95
3.437 On 7 August, Dr Metters wrote to Mr Meldrum in response to MAFF's proposals to exclude calves under 6 months of age from the ban 96 (see paragraph 3.535 in the section discussing the exemption of calves). He proposed that MAFF and DH should hold an ad hoc meeting of experts to consider the proposed calf exemption, to include Sir Richard Southwood and Dr Tyrrell. He suggested that the same meeting of experts should consider the question of abomasum tripe.
3.438 Mr Meldrum responded to Dr Metters on 14 August agreeing to arrange a meeting. 97 He suggested Mr Bradley and Dr Kimberlin also attend.
18 September: the ad-hoc meeting of experts
3.439 On abomasum and rennet the meeting notes record:
The consensus was that the abomasum, containing, as it did, a certain amount of lymphoid tissue, represented a higher risk than the other stomachs. There was also doubt about the pH effect on rennet. Dr Kimberlin agreed to look at these issues and advise. Mr Bradley would also - within the next two weeks - look at the rennet production process at a plant. 98
3.440 On 21 September, Mr Bradley minuted Mr Lawrence to advise that he would be unable to deliver further information on or about the rennet production process within the two-week timescale envisaged at the meeting of experts. 99 He commented that in his report of 13 July he had recommended that these studies were done, but had been restrained from conducting them at that time. He asked Mr Lawrence to:
Ensure administratively that no further actions are taken until (my) studies are complete. 100
27 September: meeting to discuss the responses to the consultation letter
3.441 Only a few of the responses to the consultation - from the Petfood Manufacturers Association 101, the MLC 102 and the MILG 103 - had raised tripe as an issue. Each of these bodies sought clarification on whether tripe was to be included in the ban. None of the responses provided any comments on rennet.
3.442 The main outcome of the meeting was that MAFF would continue with the drafting of regulations to implement the ban. Mr Maslin's note of the meeting recorded that in relation to tripe:
A definition of intestines should be included, making it clear that it did not cover stomachs or mesenteric fat.
3.443 With respect to abomasum and rennet, the note recorded that further scientific studies were under way and the results would be available shortly, when a decision would be taken.
3.444 A few days later Mr Lawrence minuted Mr Gummer to update him on the proposed ban, including MAFF's conclusions in the light of the consultation. On the subject of tripe and rennet he concluded that when further studies were completed further discussions would be held with DH and a submission prepared for the Minister. 104
3.445 Mr Lawrence also wrote to Dr Pickles, enclosing the note of the meeting of 27 September. 105 He copied the letter and note to Dr Metters and advised that MAFF would like to discuss the findings of Dr Kimberlin and Mr Bradley on casings, rennet and abomasum with DH.
Mr Bradley's risk assessment on rennet
3.446 Meanwhile, on 28 September, Mr Bradley had submitted his risk assessment report on rennet to Mr Meldrum and to Dr Watson. 106 The report examined the factors in rennet production influencing the risk of the BSE agent being present in the final product. He had examined abomasums from calves and older cattle collected from a rennet factory, the processes used to produce rennet at the factory and the subsequent use of rennet in other industrial processes.
3.447 On risk of infectivity of abomasum, Mr Bradley commented that it was not possible to guarantee absence of BSE infectivity. He noted that lymphoid nodules were absent in the abomasum of very young calves and increased in quantity with age. He continued:
On this basis even calves exposed to infection may not harbour infectivity in the abomasum and even if they did it would be at a very low level, and judging by natural ovine scrapie studies, would be undetectable.
With regard to adult ox reed, whilst there are variable lymphoid nodules present and in similar quantity to that in small intestine, in no instance was it formed into macroscopically visible nodes or patches . . .
This suggests a dividing line can be introduced to separate, for practical purposes and in regard to offals, tissues with a higher risk which will be excluded from the ban. The criterion would be that offals with macroscopically visible lymphoid tissue would be banned (with exceptions, if appropriate, where such tissue was removed, eg casings) others being excluded.
In this way oesophagus and tripe already cleared histologically continue to present acceptable risk as also now does abomasum.
Strictly speaking therefore only parts of the intestine containing macroscopically visible Peyer's patches would be banned, but since these cannot readily be identified in abattoir conditions it is necessary to ban (other than casings) the complete alimentary tract from duodenum to rectum. Overall then abomasum would be cleared for human consumption as black tripe despite its lymphoid content and also for rennet production. 107
3.448 Mr Bradley considered that, although pH would only have a limited effect, other chemical treatments and/or filtration might reduce any infectivity in the liquid rennet. He pointed out that if infectivity was present in source material, filtration would lead to the infectivity ending up in the waste rather than the rennet. In relation to subsequent processing (eg, in cheese-making) the dilution of the rennet at 1:4,000 would also reduce any infectivity. 108
Reappraisal of previous studies and introducing a definite and less severe criterion for risk factor in offals (macroscopically visible lymphoid tissue) enables abomasum and thus rennet to be excluded from the offal ban. This is recommended as an interim measure pending result of infectivity studies. 109
Dr Kimberlin's paper on the scientific arguments for the proposed offal ban
3.450 On 4 October, Dr Kimberlin wrote to Mr Meldrum enclosing his paper on abomasum, casings and rennet. In relation to tripe his covering letter commented:
After much thought I have assembled the arguments that avoid banning any of the tripe organs. This not only seems reasonable, but it circumvents the problems of presentation if you were to ban intestines and abomasum (but not the other parts of the stomach) which would also make it awkward to deal with rennet. 110
3.451 Dr Kimberlin's paper commented that the proposed ban on brain, spinal cord, thymus, spleen and tonsils was well-founded. The paper considered that the tripe organs should be excluded from the proposed ban and presented several arguments to support this proposition. His arguments were broadly consistent with those presented by Mr Bradley in his report of 28 September (see paragraphs 3.446-3.449). In particular:
Most of the infectivity in the intestines seems to be associated with the large masses of fixed lymphoreticular tissue: Peyer's patches . . .
Peyer's patches are rarely if ever found in the tripe organs. Certainly the amounts would be very much smaller than in either the small or large intestines and it is important to recognise the quantitative differences . . .
Unless future studies show convincingly that the amounts of LRS (lympho-reticular system) tissue in the tripe organs approach the total relative mass of Peyer's patches in the intestines, there is no basis for banning the use of any of the tripes, including abomasum. However, it is important to measure the infectivity in these tissues as soon as possible. 111
3.452 On rennet Dr Kimberlin considered that there was little scope for chemical inactivation of any infectivity during the manufacture of rennet. Nevertheless physical processing during manufacture, particularly the repeated filtration steps, would ensure that the rennet was free from significant levels of infectivity, even if there were appreciable levels of infectivity in the abomasum. 112
Dr Pickles briefs the CMO for a meeting with Mr Gummer
3.453 On 5 October, Dr Pickles prepared a briefing note for a meeting planned between the CMO, Sir Donald Acheson, and Mr Gummer on 16 October. In the note, Dr Pickles mentioned that since Mr Gummer had taken office, he had already had several briefing sessions on BSE, 'but may want to hear CMO confirm that the risk to humans is considered remote'. In relation to the proposed SBO ban she commented:
This is a very important issue for Mr Gummer and he may want to discuss the rationale with CMO. Although the ban goes beyond what Southwood recommended, and has led to unforeseen practical, economic and international difficulties, there can be no turning back. The theoretical risk of contamination with agent, by analogy with scrapie, lies with lymphoid and nervous tissue. Measures currently proposed in ban would eliminate large concentrations of such tissue (spleen, thymus, tonsils, unstripped intestines, brain, mature spinal cord), but it has to be recognised that it is impossible to eliminate all lymphoid and nervous tissue, which includes peripheral nodes and nerves intimately associated with the main edible parts.
But even if BSE agent is present in small amounts in uncooked beef and beef products - and accepting that cooking reduces levels but may not eliminate agent - the chance of BSE being transmissible by the oral route is remote. Scientific evidence is that BSE is identical to/close to scrapie, and scrapie-infected mutton has presented no risk over the centuries. 113
19 October: Mr Meldrum writes to Dr Jeremy Metters on rennet, abomasum and casings
3.454 Mr Meldrum's letter of 19 October advised Dr Metters of the results of the further investigations by Mr Bradley and Dr Kimberlin into the production of rennet and casings. 114 He enclosed Dr Kimberlin's paper of 4 October (see paragraphs 3.450-3.452).
3.455 On tripe and rennet Mr Meldrum proposed:
We suggest that we can separate offals for practical purposes on the basis that those with macroscopically visible lymphoid tissues would be banned whilst others would be excluded. In this way oesophagus and tripe would continue to present a low and acceptable risk as would the abomasum.
On this basis and with further knowledge of the rennet production process we suggest that both abomasums and rennet should be excluded from the ban. The latter in any event goes through a number of processes which will reduce the possibility of presence of the agent and, finally, the dilution factor in cheese making would obviate any residual risk. 115
Mr Meldrum seeks comments from Sir Richard Southwood and Dr Tyrrell on how to proceed with rennet, abomasum and casings
3.456 Mr Meldrum wrote to Sir Richard Southwood and Dr Tyrrell on 23 October enclosing a copy of the letter and attachments which he had sent to Dr Metters on 19 October. 116 His purpose was to update them on the studies undertaken by Mr Bradley and Dr Kimberlin and to seek their comments on the proposed approach in the light of these studies. He advised that Dr Metters was broadly content with the proposed approach but would be giving his final view shortly.
3.457 Sir Richard responded on 26 October, stating he was happy with Mr Meldrum's recommendations. 117 He did not offer any specific comments on tripe or rennet. Dr Tyrrell responded on 6 November and agreed with Mr Meldrum's conclusions on exempting rennet. 118 He did not offer any specific comments on tripe.
30 October: DH recommends MAFF to proceed as they think fit with the proposals
3.458 Dr Metters replied to Mr Meldrum's letter on 30 October. 119 He noted that consideration of which tissues to ban needed to be seen in the context of the Southwood Report: