CHAIRMAN BROWN: Yes, I don't think anybody is going to be able to give you a precise answer.
In view of this question that you raise, I'm reminded that Dr. Bob Brewer in the audience emphasized to me something which may have escaped the attention of other people. The rendering process is exposing the material not to autoclave type conditions, but to dry heat. It's a heat transfer from steam, wet heat, to material. So, basically, it's like putting it on a stove in a pot in terms of the heat, the type of heat that is being used. We already know that dry heat is incredibly less effective in inactivation of these agents, or any other agent for that matter, than is wet heat. So, atmospheric pressure using temperatures even of 132 or 140 are not anywhere near as heating to these temperatures under autoclave conditions more than a single bar, more than atmospheric pressure.
So, you're quite right. We don't have information about zero infectivity. The idea of reducing is the idea that is going to have to be uppermost in mind. Even a temperature of 121 reduces the infectivity. And as I think we are becoming aware from the whole BSE problem, it is possible that very small reductions can have very large results.
Other questions? Barbara?
MS. HARRELL: Okay, Mitch Kilanowski made a statement that edible tallow does not contain head and spinal cord. Are you saying that because those raw materials are not used in producing tallow? What brings that to mind is that I remember I think about a year, they said that spinal cord was found in ground beef. I was just trying to see how you could make an emphatic statement.
DR. HUESTON: At this point, I understand that it is being taken out.
MS. HARRELL: Is being --
DR. HUESTON: Being taken out.
MS. HARRELL: -- not has not been?
DR. HUESTON: Heads are being taken out and spinal cords, as I understand it.
MS. HARRELL: Thank you.
CHAIRMAN BROWN: If there are no other questions, we will now take the lunch break. It is 12:00 noon exactly, and we will reconvene at 1:00 p.m.
DR. FREAS: There is a table downstairs reserved for Committee members. If the Committee members would sit there, it might speed service and you'd be back on time. Thank you.
(Whereupon, the meeting was recessed at 11:55 a.m., to reconvene later this same day.)
CHAIRMAN BROWN: Good afternoon. We are introducing this afternoon's tallow derivatives presentations with an opening talk by Dr. Gerald Pflug who, according to the program, represents the Soap and Detergent Association.
Is that correct, Dr. Pflug?
DR. PFLUG: Good afternoon, ladies and gentlemen. My name is Gerry Pflug and I'm president of the Soap and Detergent Association.
The association was founded in 1926 and is a North American based trade association whose members manufacture in the United States, Canada and Mexico. The Association today has approximately 150 member companies representing those that manufacture the cleaning products such as Proctor & Gamble, Lever, Colgate, Amway, Dial, and Reckitt & Coleman to cite a few; the raw material suppliers such as Shell, Candia Vista, Union Carbide, Steppon and Witco. Also included are the oleochemical producers and finally, the packaging manufacturers.
The Association represents well over 90 percent of the cleaning products produced and sold in North America for both household and industrial and institutional uses. The association has four divisions. The first and the largest is the Technical and Materials Division which consists of product formulator companies, as well as raw material suppliers. The second division is the Household Division which consists primarily of household products companies. The third division is a division which consists of companies who supply the industrial and institutional needs of industry, and finally, the Oleochemicals Division.
Approximately 18 months ago, the SDA under the leadership of its Oleochemical Division conducted a survey of its members to document the methods and conditions used for the feedstocks to produce oleochemicals. The SDA worked together with the FDA to develop the ultimate questionnaires that were used in this survey. The results were tabulated by an outside consulting firm and overseen by SDA general counsel. In August of 1997, the initial document representing the results of the SDA survey was completed and submitted to the FDA. I think you've all seen that. A follow-up meeting was held with the FDA to discuss the document and identify further information which was needed. A supplement to the original document was submitted in March of 1998 and today, an addendum to the supplement is available.
This survey represents between 95 and 100 percent of the major uses of oleochemicals in the United States. It is the belief of SDA and its members that the data generated and presented with regard to temperatures, pressures and times demonstrates how the industry helps assure the safety of oleochemicals produced in the United States. They are representative of typical operating conditions in the industry. We welcome any questions you may have with regard to the survey, its conduct, or its results.
This afternoon you will hear presentations from the following. Dr. Charles Green of Witco, who is director of Regulatory and Toxicology for the Oleochemicals/Surfactants Group who will discuss feedstocks, the overview of the US oleochemical industry, and production processes. He will be followed by Dr. Philip Merrell of Mallinckrodt who is a research associate in the Specialty Chemicals R&D Department. He will discuss the manufacturing process of magnesium stearate. Next will be Stan Gorak from ICI Americas who is manager of Quality and Process Chemistries. Stan will discuss the manufacturing processes for polysorbates. Dennis Walker of Proctor & Gamble who is regulatory manager for Proctor & Gamble's Chemical Group will discuss oleochemical safety in the United States. Finally, Dr. Frederick Bader of Centicor, VP for worldwide operations will discus the safety of pharmaceuticals.
We thank you for the opportunity to present our findings. Thank you.
CHAIRMAN BROWN: Thanks very much, Dr. Pflug.
Dr. Green has a block of one hour. If he chooses to use it, that's fine. We won't interrupt him. Following his presentations, plural, we'll probably have time for one or two others before the break. We shall see.
DR. GREEN: First of all, I want to thank you for inviting me to speak here. I hope that possibly some of the things I say might answer some of the questions that were asked this morning. I'm going to try to elute to some of them in further explanations that would give you a clearer understanding.
The safety of tallow and tallow derivatives cited in the December publication of Journal of Veterinarian Records by Dr. Taylor is going to be what we consider our base to make comparison against. Dr. Taylor's publication demonstrated a minimal margin of safety needed for production standards was 20 minutes with a temperature of 133 degrees C and three bars, in which we are very generously going to call that 48 psi, pounds per square inch. In industry, we will use terms like psi versus bars because of the way the computers are programmed, we need the flexibility and trimline analysis to use a much more flexible mechanism. But I will always give you both comparisons. This is pretty much true throughout the world.
One of the things that I would like to point out is that Witco is a multinational company. We have plants not only in the United States. We have plants in Europe and are presently putting plants in Asia. This is very true of all of the multinational companies have plants all over the world. One of the things that you might want to be aware of is plants do interplant transfer of products where they may not have all the equipment that they use in full production in one location. They may do partial production in one location and move it to another location. Specifically to that reference, I will address a question that has come up on why tallow would be imported into the United States. There's a explanation for answering that question and why.
The oleochemical industry will show that their method of processing tallow and then taking the processed tallow into derivatives significantly exceeds the minimal standard as set by Dr. Taylor's publication. The Soap and Detergent Association survey reflects representation of nearly all the industry, multi-step processing under harsh conditions and we are going to emphasize time, temperature and pressure throughout the entire presentation. I also want to state that Witco processes not only tallow, but we process vegetable oils, and fish oils, and everything. It's the same set of conditions for processing. It's the same type of equipment. It is identical irrespective of which triglyceride you're using.
I'm going to focus on various manufacturing procedures. In particular, I'm going to address saponification, hydrolysis -- we call it splitting, but that's a manufacturing term. In a laboratory, it's called hydrolysis -- and transesterification. The three routes that tallow is converted into derivatives and refined into fatty acids and ester. We're going to talk about the operating conditions, routine and process quality testing. The processes presented will apply to both edible tallow and inedible.
Let me say this, in processing tallow, the equipment and the conditions are identical. You do not process edible tallow in the same equipment you process inedible tallow. They're kept separate. The rail cars are brought into the plants separately. They're not mixed up. You do not go through common lines, common pumps, common headers or anything at a plant. They are totally separate.
Tallow derivatives touch us in many ways, improving the quality of our life in drugs, cosmetics, food, food additives and hundreds of other uses. Tallow to us is just a building block, much like ethylene gas is to the plastic industry or crude oil is to industry, or you use it as a building block to make many, many down field derivatives. These derivatives are used in almost all facets of the market world. I'm going to focus on the issue here today of food and pharmaceuticals and cosmetics.
Quickly, I'm going through this. This is just an edible versus inedible. It's a comparison of 1993 to '96. This is in millions of pounds. We seem to play around with tons and pounds, so I'm going to stick with pounds. I'm a chemist, so I prefer to stick with one term.
The consumption, this is edible products. It just shows the baking fats and others. This is just to show there's a slight dip in this because of certain trends towards using vegetable source in certain market areas. This simply shows an overview. I'm only going to elaborate very quickly on it. It just shows the soap consumption is pretty constant. The feed consumption is a large portion in tallow. The lubricants and the fatty acids is pretty uniform.
This is a quick overview of how you have hydrolysis, or what we call splitting. When we mean splitting, we mean split the fatty acid away from the glycerin. We recognize that the predominant species are stearic, oleic and palmitic acids.
In transesterification, you're taking the tallow and putting methyl alcohol in there. You're converting it and doing a transesterification straight through to the methyl ester. What we do then, and what is done then, you take the methyl ester -- the reasons for converting to methyl esters if you're analytically -- and you know anything about analytical labs, you want to analyze fatty acids, you make the methyl ester because you can get it down to the gas chromatograph and you get a much cleaner separation.
The same is very true if you want to separate out high purity stearic, high purity oleic, or high purity palmitic. By having the methyl ester near distillation tower in the plant, it's so much easier to separate it. That is part of the reason why certain companies using methyl ester production in their transesterification because the next step they do after that is to convert the methyl ester, again by transesterification and reduction with hydrogenation to the alcohol. That's how you get high purity stearic acid. This has its own derivatization after that. I'll touch that briefly, later.
Processing in our plants are computer controlled. Let me state this. Witco processes more than 300 million pounds of tallow every year. If you take the value of down time, maintenance on equipment, that equates out to we process approximately one million pounds every day, 365 days out of the year. When we talk about processing in something of this magnitude, you have to have automated equipment and it's very large equipment.
Now, what we do -- and I said I would elute to a question this morning -- one of the first steps -- let me have the next slide -- I want to do an overview again on each phase, keeping in mind that we're going to talk about time, temperature and pressure. You'll see when I start through this, what that really means.
We're going to do hydrogenation. We're going to do hydrolysis distillation, the separation of the fatty acids, separation of glycerin, conversion of glycerin to US pig glycerin. Then we're going to derivatives and then we're going to means.
What we do first, we take the edible tallow and we do a partial hydrogenation on it before it is ever split. Now at that point, I'll show you how you can have importation of tallow into the United States. We are a multinational company. Our -- is here in the United States, but we have plants all over Europe. We have hydrogenation equipment here that's much more sophisticated than plants in Europe. It is not uncommon for us to start a partial hydrogenation before we ship products to our plants overseas. The same thing happens when you have plants whose major facilities are overseas and they have plants in the United States. They start hydrogenation there and then import it here.
The way that's commonly referred to as hard tallow, soft tallow. What do you mean by hard tallow, soft tallow? Hard tallow is where you have hydrogenated out unsaturation, pushed it up to a pretty high extent. If you're going to convert it to fatty alcohols, you prefer stearic alcohol. So, there's a reason why you would do a partial hydrogenation before you imported it.
Now, when we start out, before we ever go to splitting the tallow, we do a partial hydrogenation. Here are your conditions. You're going to take tallow -- oh, correction. I'm a little off here. This is saponification tallow. I'm going to cover that right quick like. Soap manufacturing generally is not done straight tallow. It's a blend. Generally, it's an 80/20 blend. Everybody has a little bit different in their formulation. Your time is one to three hours. Your temperature is 100 to 115 degrees C, and your pressure is atmospheric. But you're operating under a caustic condition, at least 12 molar.
This is not the only way you can make soap. There are companies that take fatty acids and make soaps from fatty acids. Now, I will say one thing. In the chart on the board here where you have inedible tallow going to fatty acids, I can safely make this statement since I'm on not only the Soap and Detergent Association. I'm on other associations where all the fatty acid manufacturers in the United States are involved. Not one single company manufactures fatty acids from saponification. When you saponify it with an alkali, you've got a salt. Now, you've got to neutralize the salt off. You've got to filter the salt out. You do not do that. In the old days, it might have been done. Since 1980, nobody does that in the United States, not the fatty acid through saponification.
I think that the understanding of soap -- soap is not a single time where you just saponify it and you've got it. You do a saponification. You drain off so much of the glycerin. You saponify it again. You drain off the glycerin. You go through a multi-step, multi-contact with alkali. You mill it. Then you blend back various components. There are certain things as waxes and so forth that added the soap to control the rate at which it dissolves. They put preservatives in it. They put bacterial agents, if that's the type of bar they're making, and what-have-you. So, all of this is a multi-complex system.
CHAIRMAN BROWN: Yes, Dr. Green, what is the pH of the solution?
DR. GREEN: The pH of the solution as it starts out would be over 12.
CHAIRMAN BROWN: Not quite 13, but over 12? Somewhere between the two?
DR. GREEN: Yes, yes.
Transesterification of tallow. The time in the transesterification is six to eight hours. The temperature is 160 to 170 C and your pressure is 25 to 75 psi. The reason you're doing it at that, methanol is very hard to keep in solution when you've got it that hot. So, you have to have that much pressure to keep the methanol where it will react.
Now, when you do the second stage where you're going from the transesterification of the methyl ester to the subsequent alcohol such as predominantly seal or stearyl alcohol, you're going to have one to three hours. Now your pressure and your temperature is going to radically change. Your temperature is about 250 to 300 degrees C. Your pressure is 3,000 pounds to 4,000 pounds per square inch which is a radical change in time, temperature and pressure. This is the way that you do the transesterification.
Fatty acids and splitting. This is a process that almost everybody, not only in the United States but throughout the world, that uses this hydrolysis step uses this same procedure. You have tallow and steam, your three to four hours, and temperature is 248 to 271. Now, I've covered the entire manufacturing range in North America. Those set of temperatures will cover every person or every company that's manufacturing. The pressure will run between 710 and 730 psi. That covers all the pressures that are used in the industry.
You could have fatty acid in glycerin. Now you must distill the fatty acid -- what we call the tallow fatty acid. We're going to still that out into its components. Here is the time, temperature and pressure used to do this. Your time is about 25 minutes in the distillation tower. Your temperature is about 249 to 254 C. I don't care what you do, that fatty acids distilled at the same temperature, so that's your range. Your pressure, you're going to do it at reduced pressure. You do it under atmospheric or increased pressure, you're going to have decompositioned products of your fatty acid. Now you have separated your stearic, your palmitic and oleic acids.
This is a typical glycerin distillation. You have crude glycerin when you split or separate or hydrolysis, however you want to call it -- you get glycerin plus water. Now you're going to separate the water from the glycerin. You can not do it in a single distillation. It's a minimum two stage, and in some instances, people have to go to three stages. This is the first stage where you go up to about a 95 percent distilled glycerin. Your time is approximately one hour. Your temperature is 161 to 171 degrees C. You're operating at a reduced pressure. You must not distill glycerin at atmospheric or increased pressure or you'll polymerize it. Or you'll start degradation of it, and one of the degradation products is acrolein which is an alacromere.
Now you have distilled glycerin, but this is not USP grade glycerin. To get from distilled glycerin to USP grade glycerin, you go back up a distillation tower, 25 minutes, 166 to 171 C, and a reduced pressure, and now you'll have USP glycerin. This is how glycerin is made or distilled irrespective of its source. But this is exactly how it is distilled from tallow. Now I want to take and go from here to the derivatization section and show you the many types of derivatives you make and the conditions you're doing. But again, if you will notice, we have operated at very high temperatures either at reduced pressure or very high pressures, and we have had times far greater than 20 minutes as the minimum standard in Dr. Taylor's publication.
One thing you can do in derivatization is to take tallow, typical hydrogenated tallow, and convert it directly to the mono/diglycerides of tallow. There are two ways you make mono/diglycerides. I'm going to show you both of them. You take hydrogenated tallow, glycerin and a catalyst. Your time is about seven hours. Your temperature is 221 to 232 C, and you're operating at atmospheric pressure. This is a batch operation. Now, prior to this, I was doing continuous operation. This is a batch operation. This is why your hours go up. You'll get a mono/diglyceride. You're operating in this condition. The catalyst, incidentally, is sodium hydroxide. So, you're putting a base catalyst in there. You've got glycerin. What you're going to do is put in excess glycerin so you convert a triglyceride to a mono/diglyceride and this is how it's done.
This is how you do it taking a fatty acid. Quite often, if you take the fatty acid -- you can take stearic or oleic for that matter -- and you do this. Again, you're using the fatty acid, glycerin and a base, catalyst. The base catalyst is sodium hydroxide. Your time is six hours. Your temperature is 221 to 232 C. Your pressure is atmospheric. You get mono/diglycerides. These products are used both in pharmaceuticals and in direct food additives. They're covered under GRAS. Mono/diglycerides are commonly used in such items as no fat frying. A trade name might be something like Pam. These are the type things that you take the mono/diglycerides. There also, mono/diglycerides are then further processed. They're reacted with phosphoric, anhydride, and then neutralized with sodium carbonate. That is a standard emulsifier for chocolate. That's what makes chocolate disperse into milk. Mono/diglycerides are also used in cake mixes and direct food additives in this line. The preferential of going to stearic versus -- that's predominantly done in cake mixes.
Glycerol mono oleate. Again, you generally take oleic acid and glycerine, about two-and-a-half hours, 204 to 246 C. The reason why that's such a wide diversity, it has to do with the speed agitation in the agitator, the number of baffles in the reactor. Different companies have different setups on their equipment. The pressure, again, is a reduced pressure. You don't want to polymerize the glycerine. You'll make glycerol mono oleate. Glycerol mono oleate is used as a direct food additive, and it's also used in some pharmaceuticals and topical applications. Glycerol mono oleate is also used in some of the topical applications. It winds up as a blocking agent to prevent diaper rash.
I want to briefly talk about some of the salts made from this. Dr. Merrell will discuss magnesium stearate made a different way. There are two ways you make metallic salts of stearic acid. One of them is a fuse method and the other one we call precipitated. It's a difunctional method and he'll discuss that in detail in his part. I'm going to simply talk about the fused method for making stearates.
You wind up with the same product. It's just a matter of physical forms are different and surface areas are different. Again, you have about two hours. Your temperature is much lower but remember, this stearic acid has gone through some very high temperature than which it was prepared. Your temperature is about 74 to 88 degrees C and you're operating at atmospheric pressure. You wind up, in this case, with calcium stearate. Calcium stearate is used both in pharmaceuticals and it's extensively used in direct food additives. It's cleared under Title 21, CFR 172.860. I might also add that in the transesterification process, the fatty alcohols that are produced that are also approved for direct food applications under Title 21, CFR 172 paragraph.
This is zinc stearate. I use zinc for two reasons. Number one is, zinc stearate is applied in quite a number of topical pharmaceuticals for different purposes. Zinc stearate is used in that way and zinc stearate is used in more indirect food applications than it is direct food applications. It's not only a mould release agent, but it's an excellent antioxidant. The manufacture, again, is about six hours. It's a batch process. You're operating at higher temperatures, 129 to 141 degrees C. Your pressure is atmospheric and you wind up with zinc stearate. These are both fused type operations.