Alkylphenol Ethoxylates and Phosphates

Question:
Which Alconox detergents contain alkylphenol ethoxylates and which ones contain phosphates?

Answer:
Liquinox and Citranox contain alkylphenol ethoxylates. Alconox, Tergazyme, Alcojet, Alcotabs, and Detojet contain phosphate. Detergent 8, Luminox, Citrajet, Solujet and Tergajet contain no alkylphenol ethoxylates and no phosphates.

Plastic Container for Soak Solutions

Question:
What kind of plastic container can I use to hold a detergent soak solution?

Answer:
You can use any container that is robust enough to hold typical aqueous solutions of chemicals. A polypropylene or other chemical resistant plastic container such as HDPE (just about anything but polycarbonate or polyurethane) will work just fine for cleaning. If you have specific residue concerns, you should consider the possibility of certain metals or monomers leaching out of the plastic. For general purpose laboratory and medical cleaning this is typically not a concern because the anti-redeposition properties of the detergent are sufficient to stop anything that leaches out of the container from depositing on the substrate being cleaned.

Cleaning Filters with Tergazyme

Question:
What kind of cleaning can I expect from Tergazyme when cleaning filters with wine residues?

Answer:
We would expect Tergazyme to work very well on biofilms or microbial contamination from filters that had been repeatedly used to filter wine. It will do quite well on assorted organic residues from various components of wine. The one cleaning mechanism that Tergazyme does not have is oxidation or bleaching. This means it would not be unusual if some trace color was left of some difficult to hyrdrolyze condensed tannins or other coloring agents from the wine. Certainly Tergazyme would do something on these residues, but it would not be as dramatic as using bleach or peroxide to oxidize or even possibly metabisulfite to reduce these residues. Of course if there is a biofilm , neither bleach, peroxide, or metabisulfite will be as effective as Tergazyme.

Detergent Testing

Question:
What kinds of test soils are used in detergent testing?

Answer:
Synthetic soils are often applied to coupons to use in testing detergents. Typically a soil will be made from some kind of binding natural oil such as vegetable oil or vegetable shortening combined with a protein such as whey powder or egg powder. Additionally there may be motor oil or used motor oil; vacuum cleaner bag dust; carbon black; and clay soils. Sometimes these mixtures would have synthetic hard water such as 150 ppm hardness (2/1:Ca+2/Mg+2) mixed in. In general you want your synthetic soil to mimic the type of residue that you are trying to develop a detergent or cleaning process to clean.

Posted Inhibitory Residue Tests

Question:
How many years are the IRTs posted?

Answer:
Three years, so currently 2007, 2006 and 2005 Inhibitory Residue Tests are posted. If IRTs from years earlier than that are needed, please contact Alconox directly.

Inhibitory Residue Test

Question:
How do I get an IRT?

Answer:
To get a lot number specific inhibitory residue test to comply with accreditation guidelines requiring lot specific or annual testing, get a certificate of analysis (COA) for the detergent you have. These COA’s can be found at http://www.alconox.com/section_dealers/certif_coa.asp

Lot numbers that you will need to get your COA are found at the top of 4 lb boxes (milk cartons), above the label on bottle, and on the side of the corrugated box for larger sizes and cases. These lot numbers are a "sub lot" of a specific master lot. Once the master lot number is identified on the COA, the inhibitory residue test data can be downloaded at www.alconox.com.

Master lot numbers change in the unusual event of a significant change in raw materials or manufacturing. Master lot numbers change such that each lot can be traced to a Master lot that was tested within one year.

Inhibitory residue tests are performed for each year's worth of sub lot numbers.

IRTs for Alconox Brands

Question:
Does Alconox, Inc have IRTs for each brand?

Answer:
Yes, annually Alconox, Inc has each brand tested through an independent laboratory. Brands include Alconox, Alcotabs, Alcojet, Citranox, Citrajet, Detojet, Detergent 8, Liquinox, Luminox, Solujet, Tergajet, Tergazyme.

Inhibitory Residue Test

Question:
What is an Inhibitory Residue Test?

Answer:
The inhibitory residue test is a test of suitability of glassware for microbiology testing. It was important when labs were using phosphate detergents, but is less so now that use of phosphate is being phased out. The test is described in SM 9020B3a (Editions 18, 19) or SM 9020B4a (Editions 20, 21).

Standard Methods says to do the test "as necessary." You might ask your regulator how they interpret that.

First and foremost, it tests the detergents/soaps used for washing glassware in the microbiology section of a lab to make sure that they do not have bacteriostatic or inhibitory qualities that may affect the microbiological test that you perform (such as multiple tube fermentation technique...). Secondly, it also "checks" your washing procedure to make sure that if there are any inhibitory/bacteriostatic substances present in your soap, the cleaning process that you employ washes out any of these inhibitory substances.

Labs that are certified for drinking water microbiology have to perform the inhibitory residue test as well as the distilled water suitability test ANNUALLY. Another source of information about these tests is in EPA's "Manual for the Certification of Laboratories Analyzing Drinking Water". The most current is the 5th Edition published in 2005.

Bath Life Extension

Question:
What is the best way to monitor for bath life extension?

Answer:
To avoid potential for cross contamination, only freshly made up cleaning solutions should be used for the highest levels of critical cleaning. For industrial critical cleaning applications, high levels of cleaning can also be achieved with extended bath life. In general, a pH change of 1 unit towards neutral indicates an exhausted cleaning solution. Bath life can be extended by physical filtration of particulates, cooling and settling of sludge and skimming of oils. Bath life can also be extended by adding one half as much detergent, of the initial load, after partially depleting the cleaning life of the bath. With frequent daily use, detergent solutions can rarely be used longer than a week even with these bath life extension techniques. Conductivity, pH and % solids, by refractometer, can be used to control bath detergent concentration.

Free alkalinity titration can be used to control bath life of alkaline cleaners where the soil being cleaned depletes free alkalinity-as is often the case with oily soils. The process:

1. Titrate a new solution to determine free alkalinity.
2. Titrate the used solution to determine the percent drop in free alkalinity.
3. Add more detergent to the bath to bring the free alkalinity back to the level of the new solution. (For example if the initial solution is made up with 100 ml of cleaner concentrate and a 25% drop in free alkalinity is observed, try adding 25 ml of cleaner concentrate to recharge your solution.)

Perform a new free-alkalinity titration to confirm the recharge the first few times this recharging method is used. This is to ensure that the detergent being used is linear with respect to free alkalinity depletion. This form of bath life extension cannot run indefinitely, sludge will eventually form. Fresh solutions must be made up periodically. Bath lives can also be extended using conductivity.

Most cleaners contain conductive salts which can be detected using conductivity. Once the conductivity response of the detergent is determined, the depletion of those conductive salts can be measured. Typically, this kind of measure the bath and recharge with detergent process can be done 2-3 times before a new bath is needed.

Conductivity and Detergent Concentration

Question:
How is conductivity used to determine how much detergent concentrate to add to a cleaning solution to restore cleaning performance?

Answer:
Part of the technical information Alconox, Inc supplies for its brands are detergent concentration versus conductivity curves. By adapting these curves to your conditions and measuring the conductivity, detergent depletion and dilution can be determined. This determination can be used to figure out how much detergent to add to the cleaning solution to restore cleaning performance.

Keep in mind that, the bath will ultimately reach a point where it forms sludge (or where some other failure occurs). At that point, the bath must be dumped and a complete batch of new cleaner made up. The time to dump the bath, and start over, is generally determined using some sort of cleanliness measurement and defined in terms of number of parts cleaned or time period of bath use. Conductivity does not typically detect the point of cleaning failure, but only detects concentration of cleaner present, whether depleted or not. The following table gives specific examples of concentration vs. conductivity for several Alconox-brand cleaners. Use this data to derive the concentration of detergent from measured conductivity. Note that, conductivity is temperature dependent. Detergent solutions do not have the same slope as many default settings on temperature-correcting conductivity meters. For best results, allow hot detergent solutions to cool to a consistent temperature for comparison.

Conductivity Controller in a Machine Washer

Question:
How does a conductivity controller regulate a dosing pump in a machine washer?

Answer:
A conductivity probe would need to be set up in the sump of a machine washer. The conductivity recorded is sent to the conductivity controller that regulates the pump (usually a peristaltic pump) that dispenses the detergent into the sump. The pump dispenses until the correct conductivity is reached for the desired concentration. Typically a concentration of 0.5% or 0.1% detergent is desired. For example, for a 0.5% Solujet concentration, enough detergent concentrate is pumped into solution until the sump reaches 2.45 mS at 22 deg C (Alconox, Inc has conductivity VS concentration curves available for each brand at 22 deg C). Once the correct concentration has been reached, the wash cycle starts.

Since conductivity is temperature dependent if hot water is used a new conductivity curve must be generated that reflects the higher temperature. If the customer provides the Alconox Technical Team the higher working temperature then a curve could be generated. Alternately, if the customer has access to a conductivity meter they could simply generate the appropriate curve for their working temperature.

Washers with Non-Standard Connectors

Question:
It is not unusual for lab/glassware-washer manufacturers to make custom connectors specific that link their brand of detergent (with unique bottle dimensions) to the machine. This is strategic on the lab/glassware-washer manufactures’ part, as their customers are locked into using their detergent. These custom molded bottles are expensive and generally make the product more expensive than Alconox brands that have standard bottles. So how does Alconox suggest adjusting for the standard bottle with these types of connector set ups?

Answer:
Unfortunately we are usually unable to supply a bottle that fits the connections because the bottles are made from custom molds that are not commercially available. The way some customers use our cleaners in these washers is to pour our detergents out of their original bottles into some of the custom bottles that fit the special washer fittings. This is of course somewhat time consuming and hazardous and there must be adequate cost savings and performance improvements to justify this. In some cases, washers can be fitted with peristaltic pumps and controllers that dose in the detergent correctly from a tube that is dipped in to one of our bottles and bypass the custom fitting bottles. This would typically require an outside contractor with experience in how to retro-fit the washers, or good in-house engineering capability by the customer. We do not have this expertise. We can supply conductivity curves to a contractor or engineer to allow them to program a conductivity controller that regulates the dosing pump.

Cleaning Stainless Steel Weldments

Question:
We need recommendations for cleaning stainless steel weldments. A Walter weld cleaning machine is being used. Currently we have tried using Luminox but sometimes it does not produce satisfactory results.

Answer:
Luminox is a very light duty cleaner used to remove light oils and tiny particulates from delicate substrates. Generally, stainless steel is not considered a delicate substrate. In this case the recommendation would be 2% Citrajet at 60 deg C for 10 minutes followed by a water rinse. Citrajet is a mild organic acid cleaner (pH 2.5) that is good at removing heat scale and discoloration around weld joints as well as being a good general purpose cleaner. The cleaning results with Citrajet will be much better than luminox.

Note, if for some reason you need to use Luminox and are satisfied with the light duty cleaning it gives, I would recommend using it at a 3% concentration at 60 deg C for 10 minutes but I would not expect it to clean as well as Citrajet.

Citrajet is low foaming like Luminox and probably a low foamer is preferable to use in junction in a large dip tank. If you for some reason have a particularly oily substrates to clean, we do make a high foaming cleaner called Citranox (manuf cat no 1801 for the 1 gal size) that would give the same heat scale and discoloration cleaning while doing a better job on oily residues. I am guessing you do not have particularly oily substrates to clean and that you will be happier with the low foaming version.

Citrajet (manuf cat no 2001 for a 1 gallon size) should be available from whatever dealer you get your Luminox from such as VWR, Thomas, Cole-Parmer or other lab and health supply dealers.

Liquinox in Relation to Alconox

Question:
Is the Alconox powder equivalent to the Liquinox liquid? If these are the same could you please provide me with some sort of documentation saying that Alconox is the powdered form of Liquinox and that they are interchangeable?

Answer:
Liquinox liquid hard surface cleaner concentrate is designed to be the functional equivalent of Alconox powdered hard surface cleaner concentrate. Liquinox was designed as a liquid replacement for Alconox. For each functional ingredient in Alconox, there is a functionally equivalent ingredient present in Liquinox at a concentration designed to give functionally equivalent performance. Of the six ingredients in Liquinox, two are identical to those found in Alconox. The other four are chosen for equivalent cleaning functionality with good shelf life characteristics in a liquid form. If we just made a liquid Alconox, it would have a very poor shelf life measured in weeks.

The key ingredient for cleaning by wetting, emulsifying and dispersing is the surfactant sodium dodecylbenzene sulfonate. This ingredient is identical in both cleaners. The surface tension, which correlates with wetting, emulsifying and dispersant character, is 32 dynes per cm in both Alconox and Liquinox. Cleaning is also assisted by chelating and sequestering agents that tie up calcium, magnesium, iron and other ions that will tend to form insoluble complexes with soils. Alconox and Liquinox both contain chelating and sequestering agents that are effective for this purpose. Alconox relies on polyphosphate chelant/sequesterants, which are perfectly stable as powders, but which do not have long term stability as liquids. In Liquinox, liquid stable organic chelants are used. Alconox and Liquinox are both detectable by total organic carbon (TOC) and other surfactant detection methods. The sodium dodecylbenzene sulfonate, which will test TOC positive, is theoretically the last ingredient to rinse away in both formulations.

Xylene Equivalent

Question:
Currently we are using Xylene to clean equipment that is used with extremely non-polar compounds. Does Alconox have a cleaning product that would be equivalent to Xylene but not as harmful and dangerous to work with? It would have to be a cleaning product with a low polarity index (between 2 and 3).

Answer:
Even extremely non-polar compounds can often be emulsified by polar surfactants.
Alconox and Liquinox both contain polar surfactants that would work well at emulsifying a non-polar compound that has been found to be cleaned by xylene. The rational for this recommendation is due to the non-polar end or hydrophilic end of the surfactant that contains xylene and benzene derivatives. In theory, polar surfactants typically form micelles in aqueous solution, meaning that the hydrophilic "head" regions aggregate in contact with surrounding solvent (aqueous) and the opposite non-polar or hydrophilic ends are sequestered together at the center of the micelle sphere, interacting with the non-polar compound of interest, thus trapping the non-polar compound in the center of the sphere. Due to this nature, the interior of the micelle – hydrophobic- is able to emulsify the non-polar residues.

An initial test to determine if warm 1% Liquinox (liquid concentrate) or Alconox (powder) solution to see if it will clean the non-polar compound. Note that unlike xylene cleaning, you will need to rinse away the detergent solution after cleaning. Xylene evaporates away, detergents rinse away. Our rational for this recommendation is based on the non-polar ends of the surfactants found in Alconox and Liquinox, based on xylene and benzene You do not have to try both, either of them should work. The Alconox is more economical to use, but it is a little messy to dissolve the powder to make a cleaning solution. The Liquinox is easier to handle, dose and mix.

If this fails, then consider using a semi-aqueous cleaning system that is a combination of surfactants and solvents that may be able to act as cosolvents for your non-polar residue. I would recommend trying a 5% Detergent 8 solution, but only if Alconox or Liquinox fails. Detergent 8 is a corrosive liquid that requires wearing rubber gloves and eye protection. Detergent 8 contains surfactants and semi-polar glycol ethers that might be able to solvate non-polar solvents.

EC 648/2004 Compliance

Question:
What Alconox brands are EC 648/2004 compliant?

Answer:
Alconox, Alcotabs, Citrajet, Detojet, Tergajet, Tergazyme

Etching During Cleaning

Question:
My system has the following materials in it: CPVC, stainless steel, cast iron and copper; should I expect an 8% Citrajet solution to etch any of these materials?

Answer:
No etching will occur on CPVC, Stainless Steel, cast iron and copper from 8% Citrajet. Cast iron might rust in the rinse water, especially if you use hot rinse water. Use water below 120 deg F to rinse cast iron and then dry quickly.

Cleaning Light Bulb Filaments

Question:
How do you clean oxides from light bulb filaments?

Answer:
When cleaning oxides from light bulb filaments our recommendation is 8% Citrajet for a contact time of at least 3 seconds at about 140 deg F. In principle, every 10 deg C you go up, doubles the cleaning speed. At 185 deg F, you would be roughly 20 deg C

Pre-soaking Pipettes

Question:
Why is it important to pre-soak pipettes in 1% Alconox or Liquinox before washing in pipette siphon washer with Alcotabs?

Answer:
The most common problem in pipette cleaning is residues that dry on after use and prior to cleaning. This problem is attributed to the failure to pre-soak the pipettes immediately after use. Our technical experts at Alconox recommend placing soiled pipettes in 1% Alconox or Liquinox solution immediately. For the purpose of detergency, it does not matter if pipettes are place tips up or tips down during pre-soak. The important thing is to make sure the pipette is completely immersed in solution with no part exposed to air where there would be a meniscus to potentially leave a ring or even an etch the pipette. For fewer broken pipette tips, it is recommended to place pipettes tips upward, if possible. However, for cleaning extremely viscous or difficult residues there is possibly a theoretical advantage to putting the pipettes in tips down to pre-soak because when they are lifted out of the pre-soak any loosely adhered residue or particulate will drain out the bottom and not have to pass thru the entire length of the pipette before it is removed.

Washing Pipettes

Question:
Is there a CAP approved procedure for washing pipettes?

Answer:
There is no CAP approved procedure for washing pipettes. Alconox, Inc recommends using Alcotabs in combination with a pipette siphon washer after a pre-soak with Alconox or Liquinox for effective batch pipette cleaning for laboratory use.
Our suggested directions are to first completely immerse pipettes immediately after use in a pre-soak solution of 1% Alconox or 1% Liquinox. When ready to clean drop an ALCOTAB into bottom of siphon pipette washer. Place pipettes in holder into the washer. Turn on cold or warm water at a rate that will fill the washer and completely cover all pipettes, then drain to the bottom during each cycle. Run water until ALCOTAB has completely dissolved, continue running water to rinse thoroughly (may take an hour to complete washing and rinsing). For analytical or tissue culture work use distilled or deionized water for final rinse.