I know, i know, there are studies out the wazoo about everything, but thought you might take a look. I know how you hate to read long journals..... but suck it up. LOL
Read this over at SBI by SV-1:
Why I don't autoclave/bake my gear. - By SV-1
I've seen a lot of info on the board lately about how using an autoclave or pressure cooker will sterilize oil based AAS, well after a good bit of research everything I've been able to find states the exact opposite.
To start here is a quote by Justin, a moderator at UK Muscle:
Quote:
Clearing up some misconceptions
Heat sterilisation of oil will not be successful by using 250F.
250F is the heat used by a certain class of autoclave. The autoclave uses pressure also to achieve wet sterilisation, this method will work for aqueous solutions but will NOT sterilise oil. If heat is the chosen method to sterilise oil, then you must sterilise by dry heat methods, i.e. 150-170C (302 - 338F) for 1-4 hrs, (type and volume depending) which can be detrimental to certain hormone preparations.
Divert your attentions to using clean practises, filtering with a 0.22um membrane filter and incorporating a Bacteriostatic agent (BA).
I found the following to support this quote.
From the FLINDERS UNIVERSITY OF SOUTH AUSTRALIA - FACULTY OF SCIENCE AND ENGINEERING
SCHOOL OF BIOLOGICAL SCIENCES USE AND TRAINING FOR AUTOCLAVES
"Ensure that the material is autoclavable – Oils, waxes, some plastics, flammable materials and samples
containing solvents or substances that may emit toxic fumes should not be autoclaved"
Full document here:
http://www.scieng.flinders.edu.au/b...s/Autoclave.pdf
In the article Sterilization and Disinfection it says:
"Dry heat is used for the sterilization of anhydrous oils, greases, powders, etc., that cannot be easily permeated by steam. Dry heat is less efficient than wet-heat sterilization and requires longer times or higher temperatures; specific time and temperature must be determined for each type of material being sterilized.
Sterilization can usually be accomplished at 160-170C (320-338F) for periods of 2-4 hours. Higher temperatures and shorter times may be used for heat resistant materials. The heat transfer properties and arrangement of articles in the load are critical to insuring effective sterilization."
and
Steam Sterilization Disadvantages
"Unsuitable method for sterilization of anhydrous oils, greases and powders."
Full document:
http://www2.ncsu.edu/ncsu/ehs/www99...BioSterDis.html
The World of Autoclaves article gives a partial explanation why:
The time required to kill a known population of microorganisms in a specific suspension at a particular temperature is referred to as thermal death time (TDT). However, fats and oils slow heat penetration and increase TDT.
Full article:
http://esf.uvm.edu/uvmsafety/labsaf...autoclaves.html
Dry Heat Sterilization:
-Sterilization in the absence of water.
-Oven heated at 160 to 170 ° C for 2 to 3 hours.
Full article:
http://www.uta.edu/biology/badon/cl...Lecture 6.pdf
DRY HEAT STERILIZATION:
Equipment: Oven
Method: Dry heat sterilization is carried out at 160 deg C. to 170 deg C. for 2 to 4 hrs.
Application: Glassware, Fixed oils, Thermostable powders
STEAM STERILIZATION:
Equipment: Autoclave
Disadvantages: 1. Cannot use for oily preparation (oil base ointment)
http://webusers.xula.edu/tmandal/ph...ics/STERILZ.PPT
"Fats and oils have a great protective effect on microorganisms and their spores by
interfering with the penetration of wet heat. As has been noted, wet heat at a given temperature is more lethal
than dry heat, because moisture is an effective conductor of heat and penetrates into microbial cells and spores.
If microorganisms are trapped within fat globules, then moisture can less readily penetrate into the cells and
heating becomes more like dry heat."
http://www.vhall.nl/International/C...reservation.pdf
Finally here is an advertisement for an ALL AMERICAN Electric Autoclave Model 25X, a $750 Sterilizer/Autoclave. Which says very clearly in the last line, "Not to be used to sterilize oils and powders."
So if you're counting on autoclaving/pressure cooking or baking (at any temp/time that wont fry your gear) to give you a sterile oil based product, think again.
Then there's the whole issue of endotoxins and pyrogens. Again the heat needed to kill them will also fry your gear.
"Endotoxin is relatively heat stable. It will survive common heat-based disinfection and sterilization procedures. Hence, sterile items are not necessarily free from endotoxin."
http://www.acciusa.com/cts/endotoxin.html
"Different endotoxins differ in their degree of toxicity, but all are heat stable and can tolerate autoclaving."
http://www.slic2.wsu.edu:82/hurlber...ges/Chap13.html
"Endotoxins are heat stable (boiling for 30 minutes does not destabilize endotoxin)"
http://www.tjclarkinc.com/bacterial..._endotoxins.htm
"Endotoxins - Heat stable molecules present in the cell walls of gram negative bacteria that have certain characteristic toxic effects"
http://www.meridianeng.com/metalworking.html
"It is difficult to remove endotoxins from products once present. It is far better to keep finished products and components relatively endotoxin-free rather than have to remove it once present."
"Historically, vials or glass components have been rendered pyrogen-free by dry heat sterilization at high temperatures. Some texts have recommended the depyrogenation of glassware and equipment by heating at a temperature of 250 C (482 degrees Fahrenheit) for 45 minutes. It has been reported that 650 C (1202 degrees Fahrenheit) for 1 minute or 180 C (356 degrees Fahrenheit) for 4 hours, likewise, will destroy pyrogens. Studies by Tsuji et al, published in 1978, have shown that at lower temperatures (of 170 C/338 degrees Fahrenheit), thermal destruction follows second-order rate, and a 3 log reduction of endotoxin levels at lower temperatures might not be practical."
http://www.fda.gov/ora/inspect_ref/itg/itg40.html
And I'm pretty sure that those temps/times will fry the hormones we use. So, if heat sterilization isn't an option, we go back to filtration/BA, imperfect though it is.
"14.1 General: Whenever possible, products shall be sterilized in the final container preferably by heat sterilization. Certain solutions and liquids that cannot be sterilized in the final container can be filtered through a sterile filter of nominal pore size 0.22um or less, or with at least equivalent microorganism-retaining properties into a previously sterilized container, such filter can remove bacteria and moulds, but not all viruses or mycoplasmas."
http://www.medisure.com.pk/drug_law/CGMP.html
And in the end it's just not necessary IMO. Maybe this will help convince some people that they're not gonna die if they don't bake the sh*t out of their juice. Concentrate on clean conditions, proper technique, use a good filter (.2 micron) and you should be fine.
Development of a Multidose Formulation for a Humanized Monoclonal Antibody Using Experimental Design Techniques
"The efficacy of the preservative against various microorganisms was measured using a modified USP/EP PET (referred to as preservative screening test in this document). Tests were conducted at Microconsult Inc (Dallas, TX). In the procedure, formulations were tested against the following microorganisms: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. The 3 bacterial strains were inoculated together at a total concentration of ~105 cfu/mL, as were the 2 fungi. Samples were incubated for 7 days at room temperature (25°C), and the total bacterial and fungal counts were measured using a colony counter. The log reduction (LR) values for the bacterial and fungal counts were calculated as log (initial count/final count)."
"Results of the preservative screening tests showed that the formulations containing 0.75% and 0.5% benzyl alcohol are potential candidates to meet the USP/EP criteria (Table 4). Both formulations demonstrated a complete kill of the tested bacterial and fungal species after 7 days. For all other samples, either the total bacterial count after 7 days was too numerous to count, or no effective reduction in the bacterial count was observed."
"Benzyl alcohol caused significant aggregation at high concentrations (≥1.0%); however, it was the most effective preservative in maintaining antimicrobial efficacy against bacteria and fungi."
Read this over at SBI by SV-1:
Why I don't autoclave/bake my gear. - By SV-1
I've seen a lot of info on the board lately about how using an autoclave or pressure cooker will sterilize oil based AAS, well after a good bit of research everything I've been able to find states the exact opposite.
To start here is a quote by Justin, a moderator at UK Muscle:
Quote:
Clearing up some misconceptions
Heat sterilisation of oil will not be successful by using 250F.
250F is the heat used by a certain class of autoclave. The autoclave uses pressure also to achieve wet sterilisation, this method will work for aqueous solutions but will NOT sterilise oil. If heat is the chosen method to sterilise oil, then you must sterilise by dry heat methods, i.e. 150-170C (302 - 338F) for 1-4 hrs, (type and volume depending) which can be detrimental to certain hormone preparations.
Divert your attentions to using clean practises, filtering with a 0.22um membrane filter and incorporating a Bacteriostatic agent (BA).
I found the following to support this quote.
From the FLINDERS UNIVERSITY OF SOUTH AUSTRALIA - FACULTY OF SCIENCE AND ENGINEERING
SCHOOL OF BIOLOGICAL SCIENCES USE AND TRAINING FOR AUTOCLAVES
"Ensure that the material is autoclavable – Oils, waxes, some plastics, flammable materials and samples
containing solvents or substances that may emit toxic fumes should not be autoclaved"
Full document here:
http://www.scieng.flinders.edu.au/b...s/Autoclave.pdf
In the article Sterilization and Disinfection it says:
"Dry heat is used for the sterilization of anhydrous oils, greases, powders, etc., that cannot be easily permeated by steam. Dry heat is less efficient than wet-heat sterilization and requires longer times or higher temperatures; specific time and temperature must be determined for each type of material being sterilized.
Sterilization can usually be accomplished at 160-170C (320-338F) for periods of 2-4 hours. Higher temperatures and shorter times may be used for heat resistant materials. The heat transfer properties and arrangement of articles in the load are critical to insuring effective sterilization."
and
Steam Sterilization Disadvantages
"Unsuitable method for sterilization of anhydrous oils, greases and powders."
Full document:
http://www2.ncsu.edu/ncsu/ehs/www99...BioSterDis.html
The World of Autoclaves article gives a partial explanation why:
The time required to kill a known population of microorganisms in a specific suspension at a particular temperature is referred to as thermal death time (TDT). However, fats and oils slow heat penetration and increase TDT.
Full article:
http://esf.uvm.edu/uvmsafety/labsaf...autoclaves.html
Dry Heat Sterilization:
-Sterilization in the absence of water.
-Oven heated at 160 to 170 ° C for 2 to 3 hours.
Full article:
http://www.uta.edu/biology/badon/cl...Lecture 6.pdf
DRY HEAT STERILIZATION:
Equipment: Oven
Method: Dry heat sterilization is carried out at 160 deg C. to 170 deg C. for 2 to 4 hrs.
Application: Glassware, Fixed oils, Thermostable powders
STEAM STERILIZATION:
Equipment: Autoclave
Disadvantages: 1. Cannot use for oily preparation (oil base ointment)
http://webusers.xula.edu/tmandal/ph...ics/STERILZ.PPT
"Fats and oils have a great protective effect on microorganisms and their spores by
interfering with the penetration of wet heat. As has been noted, wet heat at a given temperature is more lethal
than dry heat, because moisture is an effective conductor of heat and penetrates into microbial cells and spores.
If microorganisms are trapped within fat globules, then moisture can less readily penetrate into the cells and
heating becomes more like dry heat."
http://www.vhall.nl/International/C...reservation.pdf
Finally here is an advertisement for an ALL AMERICAN Electric Autoclave Model 25X, a $750 Sterilizer/Autoclave. Which says very clearly in the last line, "Not to be used to sterilize oils and powders."
So if you're counting on autoclaving/pressure cooking or baking (at any temp/time that wont fry your gear) to give you a sterile oil based product, think again.
Then there's the whole issue of endotoxins and pyrogens. Again the heat needed to kill them will also fry your gear.
"Endotoxin is relatively heat stable. It will survive common heat-based disinfection and sterilization procedures. Hence, sterile items are not necessarily free from endotoxin."
http://www.acciusa.com/cts/endotoxin.html
"Different endotoxins differ in their degree of toxicity, but all are heat stable and can tolerate autoclaving."
http://www.slic2.wsu.edu:82/hurlber...ges/Chap13.html
"Endotoxins are heat stable (boiling for 30 minutes does not destabilize endotoxin)"
http://www.tjclarkinc.com/bacterial..._endotoxins.htm
"Endotoxins - Heat stable molecules present in the cell walls of gram negative bacteria that have certain characteristic toxic effects"
http://www.meridianeng.com/metalworking.html
"It is difficult to remove endotoxins from products once present. It is far better to keep finished products and components relatively endotoxin-free rather than have to remove it once present."
"Historically, vials or glass components have been rendered pyrogen-free by dry heat sterilization at high temperatures. Some texts have recommended the depyrogenation of glassware and equipment by heating at a temperature of 250 C (482 degrees Fahrenheit) for 45 minutes. It has been reported that 650 C (1202 degrees Fahrenheit) for 1 minute or 180 C (356 degrees Fahrenheit) for 4 hours, likewise, will destroy pyrogens. Studies by Tsuji et al, published in 1978, have shown that at lower temperatures (of 170 C/338 degrees Fahrenheit), thermal destruction follows second-order rate, and a 3 log reduction of endotoxin levels at lower temperatures might not be practical."
http://www.fda.gov/ora/inspect_ref/itg/itg40.html
And I'm pretty sure that those temps/times will fry the hormones we use. So, if heat sterilization isn't an option, we go back to filtration/BA, imperfect though it is.
"14.1 General: Whenever possible, products shall be sterilized in the final container preferably by heat sterilization. Certain solutions and liquids that cannot be sterilized in the final container can be filtered through a sterile filter of nominal pore size 0.22um or less, or with at least equivalent microorganism-retaining properties into a previously sterilized container, such filter can remove bacteria and moulds, but not all viruses or mycoplasmas."
http://www.medisure.com.pk/drug_law/CGMP.html
And in the end it's just not necessary IMO. Maybe this will help convince some people that they're not gonna die if they don't bake the sh*t out of their juice. Concentrate on clean conditions, proper technique, use a good filter (.2 micron) and you should be fine.
Development of a Multidose Formulation for a Humanized Monoclonal Antibody Using Experimental Design Techniques
"The efficacy of the preservative against various microorganisms was measured using a modified USP/EP PET (referred to as preservative screening test in this document). Tests were conducted at Microconsult Inc (Dallas, TX). In the procedure, formulations were tested against the following microorganisms: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. The 3 bacterial strains were inoculated together at a total concentration of ~105 cfu/mL, as were the 2 fungi. Samples were incubated for 7 days at room temperature (25°C), and the total bacterial and fungal counts were measured using a colony counter. The log reduction (LR) values for the bacterial and fungal counts were calculated as log (initial count/final count)."
"Results of the preservative screening tests showed that the formulations containing 0.75% and 0.5% benzyl alcohol are potential candidates to meet the USP/EP criteria (Table 4). Both formulations demonstrated a complete kill of the tested bacterial and fungal species after 7 days. For all other samples, either the total bacterial count after 7 days was too numerous to count, or no effective reduction in the bacterial count was observed."
"Benzyl alcohol caused significant aggregation at high concentrations (≥1.0%); however, it was the most effective preservative in maintaining antimicrobial efficacy against bacteria and fungi."
