ODOR CONTROL

 

How To Remove Odors From Facilities

 

By CleanLink Editorial Staff

 

 

SPONSOR LINKS:

Complete Room Deodorizing

 

Do fresheners actually kill odors and/or bacteria in the air? Can you explain the science of how this works?

McGuire: Most fresheners do not “kill” anything unless they are part disinfectant. They are simply a cover-up for the foul odor. A registered disinfectant with the proper claims is needed to kill bacteria and generally needs to be applied at the odor source to be effective. The odor itself is caused by molecules that have the ability to emit a vapor. These molecules are generally created by the bacteria. As these molecules become airborne they emit a vapor that hits the olfactory system, allowing people to then identify it as a pleasant or foul odor. To eliminate the odor, you need to choose a product that attacks the odor molecule.

 

Malik: It depends on the product formulation and its claims. An air freshener is a product designed to mask or remove unpleasant room odors.  If it is designed to mask odors only, it will overcome a malodor by overwhelming it with a stronger odor for a period of time, but it will not break the malodor down.

If an air freshener is designed to break down malodors, it will contain odor counteractants in addition to fragrance. The odor conteractants neutralize the malodor by breaking down its molecules into the air. An air freshener with odor counteracts is the best solution for a facility with offensive malodors such as smoke and rotting food that should be removed from the air.

An air sanitizer can reduce airborne bacteria making the air you breathe healthier and cleaner. The simplest definition of how it works is a molecule from the air sanitizer attaches to a bacteria molecule and causes it to become inert.

 

Ferris: Let’s take urine odors – one of the toughest cleaning professionals face. Urine odor comes from naturally occurring bacteria and uric acid crystals (crystalized urine residue). Porous damp surfaces like grout host the bacteria, which feed on urine. Uric acid crystals often stay trapped in these porous surfaces and release strong odors as the bacteria consume the urine. Humid conditions or rewetting the surface can reactivate odors. The only real way to completely eliminate odors – not just mask them – is to eliminate those naturally occurring sources of odor.

Daluga: Ideally, "clean" smells like nothing at all, and thusly, custodial executives should seek odor solutions that don't employ phony fragrances that simply cover up odors.

 

Can you over freshen when it comes to odor control? Is there such a thing as too much of a good scent?

McGuire: Of course. The best policy is to use a technology that eliminates not masks the odor. Masking is the blending of two different odors that can become just as offensive as the odor itself. Once the odor is eliminated you can use a scent to freshen the air.

 

Malik: Air fresheners formulated with odor counteracts are the optimal solution to both break down and neutralize malodors and leave a fresh scent behind. Without the odor counteractant, an air freshener masks the malodor by overwhelming it with a stronger odor, but does not neutralize the malodor.  When using multiple cleaning or odor control products, it’s ideal to ensure the fragrances complement other scents in the area to create uniformity. Competing fragrances contradict each other and can become unpleasant.

Malik: It’s important to understand the size of the area that needs odor control coverage, and match this to your system of choice, along with the supplier’s cubic foot recommendation. When continuous and consistent odor control is desired, the optimal delivery solution is a wall-mounted dispenser. Typically metered aerosols cover larger cubic feet and deliver higher doses of continuous fragrance vs. passive air systems or fan systems and gel cups. Passive air and fan dispensers disperse neutral and low fragrant oils and typically have a lower coverage area than a metered aerosol. These examples of wall mount dispensers that deliver continuous odor control coverage are great solutions for common areas such as lobbies, break rooms, restrooms, hallways and conference rooms.

Liquid and hand held sprays are good solutions for spot treatments to supplement a wall-mounted dispenser program that offers continuous odor control and/or air sanitizer benefits.

 

Daluga: A sound odor management strategy employs a number of different delivery methods for odor control products. Use of a passive solution, such as a gel that works using ambient airflow, will address odors 24/7, while sprays will address odors immediately on an at-need basis. Other products, such as air and surface liquids or laundry additives, are designed to address specific odor issues at their source (mop buckets, wash loads, etc.). Indeed, each delivery method has a place in a sound odor management strategy.

 

 

 

Some facilities are actively working towards promoting green and sustainable initiatives. Where do air fresheners fit into that type of program?

Daluga: There are myriad odor control products on the market, but very few that use natural ingredients and fit under a "green" or "eco-friendly" heading.

 

Malik: While some cleaning product categories are rated green by third-party certifiers, there are no green certification standards for air fresheners. Even without third party certification, air fresheners can fit into green and sustainable initiatives. The optimal system will depend on the facilities odor control needs and goals of the sustainable initiative. For example, passive air care systems that offer low VOC continuous air freshening without the use of batteries or any power source, or metered air care systems that offer extended battery and odor control refill life.

How do odors (good or bad) impact the perception of a facility and it’s custodial crew?

McGuire: Foul odors give the impression that the facility is dirty. Thus, a process that is designed to “eliminate” not “mask” odors is essential to provide an optimal environment. Masking a foul odor can be tricky. Facility managers need to be careful on which fragrance they choose. Not all occupants like the same fragrance and in some cases masking can make matters worse.

 

Malik: A building occupant’s first impression of cleanliness is not necessary what they see, it can be what they smell.

Fragrance has a powerful effect on human behavior. Our sense of smell can evoke strong emotional reaction and influence behavior. Facility odors, good or bad, can shape the perception of how a facility is run, and how much the facility management cares about its customers. 

Pleasant fragrances can make us feel at home, brighten our moods, deliver a sense of calm and wellbeing, or increase alertness. Foul odors, even when isolated, can leave a negative perception of the entire facility, from the custodial crew to general management.

Customers or building occupants can associate foul odors with unsanitary and unsafe conditions. Similar to odors such as smoke or gas, foul odors typically trigger us to take an immediate corrective action, such as leave the establishment.

 

Daluga: When it comes to cleanliness, perception really is reality and a foul odor immediately raises eyebrows. Likewise, when a facility smells strongly of fragrances and perfumes, there's a perception that something is being covered up — there are odors being masked by other odors.

 

Ferris: Restrooms can certainly impact consumers’ perceptions of businesses, and as a result, also impact their bottom lines. According to a survey, three in four American consumers are disgusted by urine odors and urine stains in public restrooms. Of those surveyed, two-thirds would refuse to patronize business establishments such as restaurants or hotels with unclean restrooms and more than half would likely review a business more negatively (online or offline) based on whether the restroom was clean. Research from Harvard Business School found that Yelp reviews can have a five to nine percent effect on business revenues, meaning bad reviews can translate to lower profits. Additionally, the majority of parents surveyed (70%) say a school’s restroom reflects the quality of the school, its staff and its teachers.

 

 

Restroom odors are common, but what other areas of the facility should custodial managers focus on odor control?

McGuire: It is wise not to overlook kitchen areas, lunch rooms, break rooms, smoking areas, laundry, hallways and the always present dumpster. These are all areas that can cause problems.

 

Malik: Common areas such as lobbies, break rooms, conference rooms, hallways, and locker rooms are examples of additional areas where odor control solutions such as air fresheners and air sanitizers can improve facility image, customer experience, and protect customers/employees from the spread of germs. 

 

Daluga: A good odor management strategy addresses every aspect of a facility: certainly the restrooms, but also lobbies and common areas, offices and meeting rooms. Anywhere there's people, food, etc., there's likely to be smells that someone will find unpleasant, and it's crucial to have a strategy in place that addresses odors before they become an issue.

 

 

 

 

 

Contributors:

Michael McGuire

President

Thornell Corporation

Smithville, Mo.

 

Beth Malik

Director of Marketing

Amrep, Inc.

Marietta, Ga.

 

Amanda Daluga

National Sales Manager

OMI Industries/Fresh Wave IAQ

Long Grove, Ill.

 

Brad Ferris

Senior Public Relations Manager

Clorox Professional Products Company

Oakland, Calif.

 

posted on: 8/2/2013

HAND SANITIZER USAGE

Cleanlink News 7/10/2013

Study Reveals Hand Sanitizer Efficacy

• inShare

 

With some alcohol-based hand rubs a volume of 1.1 mL is recommended per application. But researchers say it is unknown whether such a small volume is sufficient to cover both hands or whether it fulfills current efficacy standards.

To address this question of efficacy, a study was done to determine hand coverage of three hand rubs — one gel based on 70 percent ethanol, one gel based on 85 percent ethanol, and one foam based on 70 percent ethanol. Each was applied with various volumes — all products: 1.1 mL, 2 mL, 2.4 mL, 1 push and 2 pushes; only foam product: 1.1 mL foam, 2 mL foam, 2.4 mL foam. 

Fifteen subjects applied each product, which were supplemented with a fluorescent dye, after which researchers used a UV light to determine the quality of coverage. The hands of 12 subjects per experiment were artificially contaminated with Serratia marcescens and the products applied as recommended (1.1 mL for the products based on 70 percent v/v ethanol; 2 mL for the product based on 85 percent w/w ethanol). 

Researchers presented their findings in a presentation titled "Lesser and lesser — the impact of small volumes in hand disinfection on quality of hand coverage and antimicrobial efficacy" at the International Conference on Prevention and Infection Control (ICPIC 2013). The results were:
"A volume < 2 mL yielded a high rate of incomplete coverage (76% - 87%), a volume ≥ 2 mL revealed better results (18% - 40%). There was a significant difference between the five volumes used with all hand rubs (p < 0.001; analysis of variance) but not between the three hand rubs themselves (p = 0.442). Application of 1.1 mL of the hand rubs based on 70% ethanol yielded a log10-reduction of 1.85 or 1.60 log10 (ASTM E 1174-06) and failed the US FDA efficacy requirement. Application of 2 mL of the hand rub based on 85% ethanol reduced the contamination by 2.06 log10 (ASTM E 1174-06) and fulfilled the US FDA efficacy requirement. Similar results were obtained according to ASTM E 2755-10."

In conclusion, the researches found that hand rubs based on 70 percent ethanol and recommended with a volume of 1.1 mL per application are not suitable to ensure complete coverage of both hands and do not fulfill the current ASTM efficacy standard requirements.

WALNUT SHELLS IN INDUSTRY

Walnut shells are used in many polishing and/or deburring applications. Walnut shell media is used for polishing or cleaning fine metals, alloys, mechanical parts, shell cartridges, eye glass lens, rocks, stones, coral, ivory, beans, and seeds.

Jewelers use walnut shell media treated with rouge in both tumbling and vibratory applications for polishing gems and fine jewelry.

When polishing the media size should be small enough to freely pass through openings or large enough to avoid lodging in openings or crevices.

CONVENIENT WAY TO CALCULATE TANK VOLUMES

Taken from Chemical Engineering Magazine

Processing & Handling :: Liquid, Gas and Air Handling :: Tanks & vessels

June 1, 2013

Solving Vessel Equations: A Better Way

Irregularly shaped vessels present challenges for determining liquid volumes. New tools can help

Sasha Gurke Knovel Corp.

Calculating the volume of a liquid in a vessel of a complex shape is a common task for chemical engineers. However, there are several difficulties associated with accurately carrying out this calculation.

In my own experience as a chemical engineer, I have become familiar with the complexities of calculations related to determining the volume of a liquid contained in a vessel with an irregular shape.
Precise volume-determination equations are readily available for common vessel shapes. But what if you are using a vessel that is a vertical cylinder with a hemispherical top and bottom? Or, what if you are working with a horizontal elliptical vessel with concave heads? No matter the type of vessel you are working with, chemical engineers need to account for the liquids within these irregular shapes to calculate the volume properly.

Vessel-calculation challenges

Let’s begin with an example scenario. Suppose a chemical engineer works at a pharmaceutical facility that produces cough syrup. In that capacity, the engineer may have to prepare a solution in a 1,000-gal vessel or tank with an irregular shape. To prepare the proper concentration of cough syrup, he or she may need to add 50 pounds of an active pharmaceutical ingredient into sugar syrup.
Before adding anything to this liquid base to prepare the proper concentration, the exact fluid volume must be known. One option is to measure the volume using a meter pump, but this method will not produce an accurate result. The alternative is to verify the exact amount of liquid needed by calculating the volume of this irregularly shaped vessel based on the liquid level.
In this scenario, suppose that the vessel in question is a vertical cylindrical vessel comprised of a conical bottom and elliptical top. The elliptical portion of the vessel is partially filled with liquid, while the cylindrical and conical portions are fully filled (Figure 1). What should be the approach to calculating the portion that is partially filled?

 Figure 1. Calculating the volume of a liquid in an irregularly shaped vessel involves combining equations for the various portions of the vessel, such as a cylinder portion, a conical portion and an elliptical portion, in this case

To calculate the total volume, you need to combine the different equations — one for each of these three basic shapes of the vessel: the conical bottom, the elliptical top and the vertical cylinder.
At this point, two complexities arise. Engineers are forced to search through databases and manuals for the equations that are appropriate for the irregular parts of the tank, and then calculate the volume using some kind of calculation software. While many engineers favor Microsoft Excel as their calculation software of choice, keep in mind that the program was not specifically designed for entering complex equations. As a result, this process for calculating the volume of a particular vessel can be a time-consuming and inefficient process. Engineers cannot afford to waste time — they need reliable equations and quick calculations.
In a similar scenario (depicted in Figure 1), the author and colleagues first either found and verified, or derived equations, in some instances using integrals, for each shape involved. Glancing through a reliable engineering book, such as Perry’s Chemical Engineers’ Handbook, revealed nothing useful for this problem.
We had better luck conducting Internet-based research, but it was not until poring through many search results that we came across the following article by Dan Jones — “Calculating Tank Volume” (www.webcalc.com.br/blog/Tank_Volume.pdf). Also see (Chem. Eng., Sept. 2011, pp 55–63).
Using the equations provided in Jones’ article for practical calculations proved to be a problem in itself. First, the equations had to be assembled in a sensible way to account for all the shapes containing liquid in the vessel. In addition, depending on the level of the liquid you are working with, there are different equations that have to be used.
Another common frustration for chemical engineers is that the data found online must be validated as well. Often with research conducted online, the reliability and validity of the the information found is not clear or defined. Checking the validity of the equations that are found can be complicated. To be sure that an equation is validated, engineers may need to recalculate everything from scratch — which we did in this case — and of course, it ended up costing us even more time.
Once we found and validated the equations and vessel dimensions, the next step was to use a calculation tool that is easy to integrate with the data. We first turned to Microsoft Excel, probably the most-often-used tool in many engineers’ toolboxes. For most calculations and analyses, an Excel spreadsheet would suffice. Several generations of engineers now have grown up using Excel — it’s a common, inexpensive software that is readily available on most desktops and laptops. In addition to its familiarity, it’s relatively easy to input large amounts of data into Excel.
However, in this case of calculating volume in an irregularly shaped vessel, it was not. It became clear that it would become an exceedingly time-consuming process just to enter the equations and variables.
Other reasons why Excel was not the right calculation tool in this case is that programming is required with external data. Second, all calculations must be performed in a consistent system of units with conversion factors embedded in equations. This is because Excel does not automatically understand the units of measurement and does not support calculations in different unit systems unless additional programming is introduced. Third, we planned to create a browser-based application, but the Internet version of Excel has exhibited performance issues and is not highly rated by many users.
Beyond Excel, there are engineering calculation tools available such as PTC’s (Needham, Mass.; www.ptc.com) Mathcad, which has automatic unit conversion and can check equations for mathematical errors. However, a browser version of Mathcad is not available, and that limits its usefulness in cloud-based applications.

SMath

To calculate the volume of a liquid in a vessel of a complex shape, a task that should take only minutes, we tested a tool that is readily available online and that could integrate our data. We found an engineering desktop calculation tool that is both powerful and distributed free of charge — SMath Studio (en.smath.info/forum/yaf_topics12_Download-SMath-Studio.aspx).
SMath has a browser version called SMath Live. While it is functionally similar to the desktop version, it needs further development. SMath, developed specifically for engineering calculations, is now used by thousands of engineers and engineering students around the world.
This tool consists of a powerful math engine core, user-friendly worksheet-based graphical user interface (GUI) and plug-ins — some of which are open source software — that connect the core with GUI. SMath has the following features:
• The ability to handle numeric and symbolic calculations
• Capabilities for 2-D and 3-D graphs
• Software versions designed for different platforms and operating systems
• Partial support of Mathcad files (*.xmcd)
• The ability to use mathematical units (either built-in or user defined)
• Multi-language worksheets
• Multi-language interface (28 languages)
• The capacity to use programming functions directly on the worksheet
• Infrastructure to support third-party plug-ins
• An auto-complete feature with description of all supported entries
• The ability to use the tool in collaboration (via server)
• Equation snippets

Improved volume calculations

The tools chemical engineers have at their disposal are critical for maintaining high levels of productivity. Ideally, engineers should use tools that are seamless, can save time, and avoid costly errors in the workflow. One way to accomplish this is through cloud computing, where software programs and data that have traditionally resided on company servers are now located on a third party’s remote servers and are accessed via the Web.
Cloud computing assures today’s engineers quick and easy access to data from anywhere on a variety of devices. It also allows engineers to easily share data with their peers across the globe. Fortunately, as technology continues to move into the cloud, engineers will have more effective and reliable tools to integrate data, such as equations with calculation software, into their design and workflow.

FIGURE 2. A Web-based equation library can help in vessel calculations

FIGURE 3. Cloud-based calculation tools can improve engineering workflow

Currently in the early stages of development, there is an engineering cloud-based productivity tool (Figure 2) comprising of SMath Live integrated with a searchable and browsable library of common engineering equations, including those for partially filled shapes, that could help you calculate liquid volume as a function of liquid level much faster than before. A chemical engineer could use this cloud-based product to find shapes and assemble them in any reasonable combination to calculate the volume of liquid in any partially filled vessel. Such a product will be useful when integrated into engineering workflow as an early-stage design tool. The stages of a typical engineering workflow where this tool can be integrated can be seen in Figure 3.
This type of Web-based product would enable users to find and select equations for various shapes and then assemble them like Lego blocks onto an SMath Live worksheet. If you are working with any unusually shaped shells, bottoms or heads, you can build any vessel from them using smaller pieces (Figure 4). You can continue to build up to more complex shapes and calculate the volume of the entire shape or the volume of liquid in partially filled shape. The same approach could be used for calculating the volume of dry particulates, suspensions and so on.
Initial results are encouraging and can be seen in Figure 1, which shows an example of a calculation for a vertical cylindrical vessel with conical bottom and elliptical top. This example was assembled from calculations for three basic shapes: cone bottom, elliptical top and vertical cylinder. Each calculation contains limiting conditions and validation routines, as well as graphic representation of a shape. These conditions and validation routines are easily adoptable for the vessel shown in the example.

FIGURE 4. (A–H) Various standard shapes that can be combined include cylinders, cones, ellipsis and hemispherical. The diagrams and equations show some of the possible situations for volume measurement that engineers might face

A prototype of this cloud-based calculation tool is now underway. We believe that the future of engineering will be characterized by tools that integrate data and calculation software and are available in the cloud. Development and deployment of these sophisticated tools will be critical for maintaining high levels of engineering productivity in the chemical industry.

Edited by Scott Jenkins

Author

Sasha Gurke is engineering technical fellow at Knovel Corp. (240 West 37th Street, New York, NY 10018; Email: sgurke@knovel.com; Phone: 617-803-8344 ). A chemist and chemical engineer, Gurke has more than 30 years of experience in the technical information field. He co-founded Knovel in 1999 and as senior vice president, he was actively involved in product development and management. Knovel was acquired by Elsevier in 2012, and Gurke continues to play an important role in new product development and strategy. Prior to Knovel, he spent 15 years with Chemical Abstracts Service/American Chemical Society in product development and editorial positions. His industrial experience includes working as a chemist at water treatment and paint manufacturing plants. Gurke holds a master’s degree in chemical technology from St. Petersburg State University of Technology and Design.

NEW PROPERTY FOUND FOR TiO2

Investigation Into Marine Concrete Anti-Fouling Coatings

Long term ecologically sound answer to organic growth remains unsolved, however the use of titanium dioxide (TiO2) particles within coatings for concrete pavements have received considerable attention in recent years.

By Peter Hughes, Contributing Writer

Published April 1, 2013

                                                       

    

 

Marine Coatings

Marine Coatings

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Marine Fig 8

 

Our civil engineers  involved  in  the  construction  or  maintenance  of  marine  concrete structures  are  faced  with  the problem of preventing unwelcome microbial growth in an environmentally friendly  way.  A long term ecologically sound answer to organic growth remains unsolved, however the use of titanium dioxide (TiO2) particles within coatings for concrete pavements have received considerable attention in recent years as these particles can trap and decompose organic and inorganic air pollutants by a photocatalytic process (1). In spite of these promising benefits, the durability and resistance to wear of TiO2 surface coatings upon fibre reinforced marine concrete has not been evaluated. In this article, the development of fundamental research on the application of TiO2-based photocatalysis in a marine environment will be introduced. The problems encountered at a UK study site restricting a larger scale application of the technology are discussed.

Photocatalytic coatings are successfully used with many other building materials and have been shown to retard algal growth on concrete (2). In spite of these promising benefits, applications of this technology are currently limited. The durability of this technology in a marine application needs to be established before large-scale practical implementation is undertaken. Titanium dioxide (TiO2) is a white inorganic substance that is thermally stable, non-flammable and insoluble. TiO2, the oxide of the metal titanium, which is the ninth most abundant element in the earth’s crust, occurs in many rocks and mineral sands, the most economically important being ilmenite and rutile deposits. Ultra-fine (nano-scale) titanium dioxide (Anatase) was used in this research for surface treatments. The potential of titanium dioxide as a photocatalyst was discovered by (3). This process, which is similar to plant photosynthesis, allows the decomposition of water into oxygen and hydrogen in the presence of light, by means of a TiO2-anode (1). Based on this heterogeneous photocatalytic oxidation process, nitrogen oxides are oxidized into water-soluble nitrates while sulfur dioxide is oxidized into water-soluble sulfates; these substances can be washed away by moisture in the form of rainfall or seawater. The overall aim of this research, is to advance the understanding of how a photocatalytic (TiO2) coatings responds in a marine environment. This phase of work, carried out in the northwest of England, has recorded anti-fouling performance and intends to progress towards a non-toxic, environmentally-benign strategy for future industrial applications.

The ‘Development’ Tio2 Coating Used In This Research

Primary particles of ultrafine TiO2 within the development coating used was typically in the range of size from 10 to 60 nm, not only as existing discreet primary particles but as aggregates, with secondary particle sizes typically >100 nm. The coating was a stable aqueous dispersion (sol) of ultrafine TiO2 particles. Key features included an anatase crystal form with a 10 wt% of TiO2 content. The coating had a neutral pH of 8.5, with a high surface area (dry) of 300 m²/g, it dried clear, and was UV light activated with limited fluorescent light activity.  It is marketed for architectural applications.

Tio2 Coating Application In This Study

The coating procedure consisted of three independently applied layers brushed (concrete tiles) or roller applied (static site) onto the surface of concrete specimens, as per the manufacturer’s recommendation. The primer layer was applied to lower the viscosity of the material. This assisted in generating a good seal in the priming process through the filling of cracks and blowholes in the concrete surface. The primer formed a coating layer with a dry film thickness of 10µm. On top of the dried primer, an undercoat was applied after a drying time of 24h. Then, three separate topcoats were applied, each 10µm and a further 24h drying time, thus, bringing the overall thickness of the photocatalytic coating to 50µm. Although the coating was composed of a number of different layers, the comparatively short time between applications ensured that the finished complete layer did not show any distinct separate layers, but can be treated for all intents and purposes in this research as a single layer, see figure 1.

Results And Discussion

The biological complexity of the phenomenon, part of a larger study (4), referred to as marine biofouling, is enormous. It has been shown here and in previous research (5) that it is an ecological community with entities originating from all that we call life. Also, each organism has its own solution for how to find and attach on a surface, evolved during millions of years. It is the author’s view, it is impossible to invent new antifouling coatings without restricting the problem, meaning that several antifouling strategies have to be part of a holistic approach, leading to a bigger solution.

There are however several obstacles to be cleared before titanium dioxide photocatalyst technology can be adopted in the control of marine biofouling. Not only the fact that the applicability of this technology is limited considerably because the catalyst works only where there is light, but the application of a coating to composite materials such as concrete has limitations, as shown in figure 2.

The performance of the coating was observed to be heavily dependent on the underlying composite material. First of all, due to differences in intrinsic properties the synthetic fibres, in abundance at the surface of the concrete samples, inhibited a satisfactory bond between coating and substrate. The thermal coefficients of the coating were different from that of the concrete and its constituents. Thermal expansion and movement, referred to as ‘fibre pop out’, of exposed fibres instigated a cracking of the coating, as seen in figure 3, resulting in not only reduced photocatalytic activity but also structure and strength destructions.

Furthermore, the attachment of filamentous algae to the surface of the coating, seen in figure 4, was also observed to be detrimental to its long term durability. Diatoms, illustrated in figure 5, form another component of marine biofilms and act a settlement mediator for larger fouling. The diatom attachment to coatings examined showed that this single algae cell accelerated coating degradation.

Filamentous bacterial growth from within the matrix of the new concrete, as observed in figure 6, also played its part in the eventual cracking and delamination of the coating from its foundation. This previously unreported phenomena is discussed in more detail elsewhere (6). Coatings for marine concrete structures are subject to harsh environments, dynamic loads, continuous expansion and contraction by heat, rain/seawater splash, impacts from debris, erosion, micro-organisms etc. In this condition, most coatings deteriorate in a short period of time in the form of cracking, blistering, disbanding or chalking. The application of the TiO2 based coating tested in this research was not designed to defend from microbial growth from ‘within’ the concrete, effectively a living substratum, observed in figure 7. The occurrence of a bacterial biofilm formation under the coating has significantly effected the performance of the coating. A  study into the addition of TiO2 powder with an average size 21 nm (30% rutile and 70% anatase) into a bacterial colony, showed that 60–120 min were sufficient to destroy all the bacteria (7). Other workers also confirm that using lower dimension TiO2 particles leads to a faster bacterial destruction (8). These new observations of bacterial growth seen in figure 6 are detrimental to the long term durability of the coating and requires further investigation. This newly observed degradation mechanism, see figure 8, reported here, of a coating has implications for not only the construction sector.

Conclusions

Based on the analysis conducted, the following conclusions may be drawn that macro and micro synthetic fibres at the surface of concrete inhibit a strong and durable bond between the coating and the substratum, accelerating cracking and the eventual breakdown of the coating. Algal filamentous growth including diatoms attached to the surface of the coatings, applies further pressure on the integrity of the coating. Bacterial filamentous growth from within the matrix of the concrete, grows at the coating/concrete interface. This growth disrupts the bond between coating and substratum, leading to the de-lamination of the coating. Based on the results presented, further research is recommended to consider factors such as microbial growth under a coating, application methods and variation, coating composition, and long term durability. Furthermore, research in this field, needs to be developed to determine if any coatings have the potential to be effective in the long term strategy against marine biofouling.

Peter Hughes is a final year PhD student at the University of Central Lancashire, UK, investigating marine biofouling and its implications for the durability of marine concrete.

Acknowledgement
The author thanks his supervisors for their guidance. D. Fairhurst, Professor I. Sherrington, Dr. N. Renevier, Professor L.H.G. Morton, Professor P. C. Robery and Dr. L. Cunningham.
Further discussions are invited at: PHughes1@uclan.ac.uk

References
1. Fujishima, A., Rao, T., Tryk, D. Titanium dioxide photocatalysis. Journal of Photochemistry and Photobiology. 1, 2000, 1-21.
2. Peller, JR, Whitman, RL, Griffith, S, Harris, P, Peller, C, Scalziatti, J. TiO2 as a photocatalyst for control of the aquatic invasive alga, Cladophora, under natural and artificial light. Photoch. Photobio. A. 186, 2007, 212-217.
3. Fujishima, A., Honda, K. Electrochemical photolysis of water at a semiconductor electrode. Nature. 238, 1972, 8-37.
4. Hughes, P., Fairhurst, D., Sherrington, I., Renevier, N., Morton., L.H.G., Robbery, P., Cunningham, L. Microscopic examination of a new mechanism for accelerated degradation of synthetic fibre reinforced marine concrete. Construction and Building Materials. 41, 2013, 498-504.
5. Hughes, P. A new mechanism for accelerated degradation of synthetic-fibre-reinforced marine concrete. Concrete. 9, 2012, Vol. 46, 18-20.
6. Hughes, P. A study into the microbial growth within new marine concrete. Concrete. 1, 2013, Vol. 47, 34-36.
7. Saito, T, Iwase J, Horic J, Morioka T. Mode of photocatalytic bactericidal action of powdered semiconductor TiO2 on mutans streptococci. Journal of Photochem Photobio B Bio. 14, 1992, 369-379.
8. Huang, Z, Maness P, Blakem D, Wolfrum E, Smolinski S, Jacoby W. Bactericidal mode of titanium dioxide photocatalysis. J Photochem Photobio A Chem. 130, 2000, 163-170.

ADHESIVE FOR SURGERY

 

 

Mussels can be a delicious meal, but the chemistry that lets mussels stick to underwater surfaces may also provide a highly adhesive wound closure and more effective healing from surgery. In recent decades, bioadhesives, tissue sealants and hemostatic agents became the favored products to control bleeding and promote tissue healing after surgery. However, many of them have side effects or other problems, including an inability to perform well on wet tissue.

“To solve this medical problem, we looked at nature,” said Jian Yang, associate professor of bioengineering at Penn State. “There are sea creatures, like the mussel, that can stick on rocks and on ships in the ocean. They can hold on tightly without getting flushed away by the waves because the mussel can make a very powerful adhesive protein. We looked at the chemical structure of that kind of adhesive protein.”

Yang, along with University of Texas-Arlington researchers Mohammadreza Mehdizadeh, Hong Weng, Dipendra Gyawali and Liping Tang, took the biological information and developed a wholly synthetic family of adhesives. They incorporated the chemical structure from the mussel’s adhesive protein into the design of an injectable synthetic polymer. The bioadhesives, called iCMBAs, adhere well in wet environments, have controlled degradability, improved biocompatibility and lower manufacturing costs, putting them a step above current products such as fibrin glue and cyanoacrylate adhesives.

Fibrin glues are fast acting and biodegradable but have relatively poor adhesion strength. They may also carry the risk of blood-borne disease transmission and have the potential for allergic reactions due to animal-based ingredients. Cyanoacrylate adhesives offer strong adhesion, rapid setting time and strong adhesion to tissue, but they degrade slowly and may cause toxicity, often limiting their use to external applications. In addition, neither product is effective when used on wet tissue, a requirement of internal organ surgery, nor are there any current commercially available tissue adhesives or sealants appropriate for both external and internal use.

The researchers tested the newly developed iCMBAs on rats, using the adhesive and finger clamping to close three wounds for two minutes. Three other wounds were closed using sutures. The researchers reported their findings in a recent issue of Biomaterials.¹

The iCMBAs provided 2.5 to 8.0 times stronger adhesion in wet tissue conditions compared to fibrin glue. They also stopped bleeding instantly, facilitated wound healing, closed wounds without the use of sutures and offered controllable degradation.

“If you want the material to stay there for one week, we can control the polymer to degrade in one week,” said Yang. “If you want the material to stay in the wound for more than a month, we can control the synthesis to make the materials degrade in one month.”

The iCMBAs are also non-toxic, and because they are fully synthetic, they are unlikely to cause allergic reactions. Side effects were limited to mild inflammation. “If you put any synthetic materials into your body, the body will generate some inflammation,” Yang said.

The researchers are now working on improving the formula. “We are still optimizing our formulation,” he said. “We are trying to make the adhesion strength even stronger” to expand its use for things like broken bones where strong adhesion is tremendously important. The researchers are also looking at adding components that could control infection.

“We can introduce another component with anti-microbial properties, so it can do two functions at once,” said Yang.

The iCMBAs could eventually be used in a wide range of surgical disciplines from suture and staple replacement to tissue grafts to treat hernias, ulcers and burns. “There are so many applications that you can use this glue for to help in surgery,” he said.

---

NEW SAFETY DAYTA SHEETS FOR CHEMICALS, GLOBALIZED

By MAUREEN BRADY,
Managing Editor
OSHA’s updated Hazard
Communication Standard (HCS),
which conforms to the United
Nations’ Globally Harmonized System of
Classification and Labeling of Chemicals
(GHS), aims to provide a common and coherent approach to classifying chemicals and
communicating hazard information on labels
and safety data sheets. According to former
U.S. Secretary of Labor Hilda Solis, the
revised standard will “improve the quality and
consistency of hazard information, making it
safer for workers to do their jobs and easier
for employers to stay competitive.”
The three major areas of change are in
hazard classification, labels and safety data
sheets.
Hazard classification: The definitions
of hazard have been changed to provide specific
criteria for classification of health and physical
hazards, as well as classification of mixtures.
These specific criteria will help to ensure that
evaluations of hazardous effects are consistent
across manufacturers, and that labels and safety
data sheets (SDS) are more accurate as a result.
Labels: Chemical manufacturers and
importers will be required to provide a label
that includes a harmonized signal word, pictogram and hazard statement for each hazard
class and category. Precautionary statements
must also be provided.
Safety Data Sheets: Will now
have a specified 16-section format.
 While full compliance with the rule
will begin in 2015, OSHA is requiring that
employees are trained on the new label
elements (i.e., pictograms, hazard statements, precautionary statements and signal
words) and SDS format by December 1,
2013. Is your company on track to meet this
December deadline?
Why train now?
Many American and foreign chemical
manufacturers have already begun to produce
HazCom 2012/GHS-compliant labels and
SDSs. OSHA says it is important to ensure that
when employees begin to see the new labels and
SDSs in their workplaces, they will be familiar
with them, understand how to use them, and
access the information effectively. The sooner
you start training your workers, the more prepared your workers will be for these changes.
The updated HCS also stipulates that
employers must provide additional employee
training for newly identified physical or
health hazards by June 1, 2016.
Who should be trained?
The GHS states in Chapter 1.4, Section
1.4.9, the importance of training all target
audiences to recognize and interpret label
and/or SDS information, and to take appropriate action in response to chemical hazards.
Training requirements should be appropriate
for and commensurate with the nature of
the work or exposure. Key target audiences
include workers, emergency responders and
also those responsible for developing labels
and SDSs. To varying degrees, the training
needs of additional target audiences have to
be addressed. These should include training
for persons involved in transport and strategies required for educating consumers in
interpreting label information on products that
they use.
What are the GHS label
elements?
Some GHS label elements have been standardized (identical with no variation) and are
directly related to the endpoints and hazard
level. Other label elements are harmonized
with common definitions and/or principles.
(See Figure to the right.)
Symbols (hazard pictograms), signal words
and hazard statements have all been standardized and assigned to specific hazard categories and classes, as appropriate. This approach
makes it easier for countries to implement the
system and should make it easier for companies to comply with regulations based on
the GHS. Prescribed symbols, signal words
and hazard statements can be readily selected
from Annex 1 of the GHS “Purple Book.”
These standardized elements are not subject
to variation and should appear on the GHS
label as indicated in the GHS for each hazard
category/class in the system.
What is the GHS Safety
Data Sheet (SDS)?
The (Material) Safety Data Sheet (SDS)
provides comprehensive information for
use in workplace chemical management.
Employers and workers use SDSs as
sources of information about hazards and to
obtain advice on safety precautions.
The SDS should contain 16 headings.
The GHS MSDS headings, sequence and
content are similar to the ISO, EU and
Data sheets,
pictograms &
signal words
OSHA GHS training must be
completed by December 1, 2013
The Section numbers refer to the sections
in the GHS Document or "Purple Book".

DIRTY CARPETS ??

Disinfecting and Sanitizing Carpet

By William R. Griffin

OCTOBER 24, 2012

 

Those familiar with the Institute of Inspection, Cleaning and Restoration Certification (IICRC) water damage and remediation standards will quote portions of the standard that say if you have a "Level 3" black water contamination, you can't clean the carpet and/or cushion. It must be replaced.

In those cases, you often have sewage, bodily fluids or infectious materials or bio-waste in or on the carpet; of course, the realistic procedure is to remove the carpet and replace it.

Where this becomes less clear is when the spill or contamination is small, such as less than one square foot in size and is not extensive, or is primarily located on the surface of the carpet.

Can this be saturated with a disinfectant or sanitizer, for the required dwell time, and then extracted? Would it then be considered acceptable?

That's a question often debated by the experts and often a reality faced on the job by cleaning professionals.

It's not always sewage

What about the homeowner who has children and pets and wants to the have the carpet sanitized during cleaning?

What about an apartment, hotel or condo building manager who has had a tenant that had pets and wants to remove pet odors and stains?

What about a day care center where multiple children play and sleep on the carpet and occasionally vomit or have an accident involving urine or feces?

What about a carpeted hospital or nursing home that smells of urine, or the carpet on a locker room floor of a health club that smells like dirty, stale socks? Is there a way to effectively and legally disinfect or sanitize these areas?

Disinfect versus sanitize

Here's the reality: You can use a disinfectant product or solution on carpet, but that won't — according to U.S. Environmental Protection Agency (EPA) definitions — allow you to legally claim on a product label or in your advertising that you have or can disinfect carpet.

Depending on the carpet manufacturer, using a disinfectant or sanitizing product may void any warranty in existence. Some disinfectant and sanitizing products may leave a residue that can attract soil, and some products affect the performance of mill-applied stain resistance properties.

Lastly, there is no realistic "on the job" way to test, verify or validate that what you have done to disinfect or sanitize carpeting has actually been effective. There are protocols to test the effectiveness of a sanitizing chemical when used on carpet, but the tests are expensive and done only in a lab.

What the experts say

Cliff Zlotnik, former owner of Unsmoke Systems, which produced the Microban line of products that are now sold by Legend Brands, has strong feelings about disinfection.

"I do not believe that a product will be approved by the EPA to disinfect a carpet. My understanding is that the EPA's position is that only hard surfaces can be disinfected," Zlotnik said. "I also believe the EPA's current testing protocol for carpet sanitizers is flawed."

Zlotnik added that there are a number of sanitizers on the market that are approved for use on carpeting. "Most are quaternary (quat)-based, but there are also phenolic-based products on the market."

Ann Kowalecki, the product manager for Legend Brands, said this: "The most important thing is to read and follow the instructions on the label. That will tell you how to use the product, its limitations and what it can properly be used for."

Kowalecki said that this will include such things as whether the carpet needs to be cleaned first, how to dilute the product, and if it needs to be flushed after application.

"From the EPA's standpoint, you can't disinfect a carpet. That terminology relates to hard surfaces, not carpeting," Kowalecki emphasized. "But you can, if you follow the label directions, say that you will sanitize or decontaminate a carpet. From a practical standpoint, it depends on how far gone the carpet is, what it's soiled with and how much of it there is on the surface and in the backing of the carpet."

Patrick Moffett, president of Environmental Management and Engineering Inc., said that disinfecting and sanitizing carpet are two different things. "In clean and gray water losses, carpet is expected to be able to be cleaned and restored with no appreciable increase in the biological load of the carpet," he said. "If you look at chemical manufacturer disinfectant claims, they are for hard surfaces and seldom for fabrics."

How we clean and sanitize clothing is to use detergents and proper rinsing, Moffett said. "Hot water must be 140 degrees Fahrenheit and, in hospital settings, hot water must be above 160 degrees Fahrenheit. When we get carpet adhesives above 120 degrees Fahrenheit, they tend to liquefy and break apart." Using hot water is not practical in salvaging an entire sewage-soaked carpet, he said.

Also, according to Moffett, some people are promoting enzymes for disinfecting purposes. "They work to a degree, but I've not seen a product manufacturer step up to the plate and guarantee that their product killed 99.99 percent of coliform bacteria, viruses, mold and parasites in carpeting."

Rick Hoverson of Advanced Vapor Technologies Inc. said that disinfection and sanitization of carpet is difficult because of the mass and irregularity of the surface. That's why he promotes his dry vapor system.

"With dry vapor, we can get a reduction in the number of microorganisms present in a carpet and the process is quite effective against odors, dust mites and their allergens, but we can't make claims or guarantee disinfection or sanitization," Hoverson said. "Our tests prove that repeated passes and extended exposure to dry vapor are more effective than a single pass. We have found that dry vapor is more effective on thin fabrics such as cubical curtains, than thick fabrics such as carpeting."

Another issue cited by Hoverson is the fact that there are no definitive or easy ways to test the effectiveness of the results of any attempt at disinfection or sanitization of carpeting.

The botanical side

The latest advancements in botanical disinfecting technology have made it possible for products to kill micro-organisms without endangering human health, according to Sam DeAth, president of Benefect Corp. "The technology continues to advance and in 2012 we will be seeing botanical carpet sanitizers registered by the EPA — the first of their kind."

DeAth said the market is quickly becoming educated on issues regarding indoor air quality and unnecessary chemical toxicity. "Today, we have a choice to use safer, botanical products while still achieving the same results, even for carpet."

In the past, DeAth said, it was assumed that disinfectants had to be toxic to humans to do their job. He's excited that the botanical option has emerged as a viable solution. "While it's true that traditional hard surface disinfectants will likely kill any organisms that they come into contact with, antimicrobial products that are EPA registered as carpet sanitizers are specifically formulated for penetrating into porous carpet materials and to avoid binding with soils or the carpet fibers themselves, which is what quats do. So they are still a better choice."

Keep it clean, healthy and safe

If you use products or processes to sanitize carpet, the most important thing to remember is the health and well-being of yourself, your workers and your customers.

Do what is best for everyone. Keep everything clean, healthy and safe.

---

Bill Griffin is an industry consultant and trainer, and the owner of Cleaning Consultant Services Inc. He is also president of ICAN, a non-profit association comprised of industry professionals providing free consultation services through Cleaning Management Institute (CMI). Comments and questions about bidding and estimating are encouraged: (206) 849-0179;WGriffin@CleaningConsultants.com.

PROBLEMS WITH THE WATER YOU DRINK ??

 

Waste Water Processing Industry Topics

 

Water/Waste Processing

 

          Waterborne microbial disease still the greatest risk to     water supplies

 

By Joseph Cotruvo

April 01, 2013

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KEYWORDS cryptosporidium / waterborne disease / legionella / cotruvo

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Traditionally, most microbial waterborne diseases in the United States are gastrointestinal and short-term, self-resolving infections. They can include bacterial pathogens, enterovirus, rotavirus, norovirus and hepatitis A virus, or protozoa like Cryptosporidium and giardia.
Although detecting waterborne disease outbreaks is difficult, and numbers are underestimates, reported waterborne disease outbreaks in the United States have declined since implementation of the 1974 Safe Drinking Water Act. The range is from a high of 90 reported outbreaks in 1979-1982 to fewer than 10 in 2002, out of about 60,000 community water systems. In addition, surveillance for outbreaks is today better than in the past, and identification of the causative microbial pathogens has significantly improved.
The reduced outbreak incidence is probably attributable to EPA requirements for microbial quality monitoring and increased water treatment that involves filtration and disinfection of surface water and disinfection of groundwaters. However, while the number of waterborne outbreaks has declined, the portion attributable to distribution system contamination has increased.

In the public eye
Beginning in 2001 Legionaires disease was added to the surveillance and reporting system, and incidences of water-related legionellosis are being reported with some regularity worldwide. Legionellosis is a consequence of inhalation of aerosols contaminated with Legionella pneumophila and perhaps other related species.
Legionaires disease gets its name from a 1976 outbreak among attendees at an American Legion convention in Philadelphia staying at a particular hotel. There were 221 reported cases and 34 deaths from pneumonia. It required about six months of intense microbiological and chemical investigations to identify the causal bacterial agent because there was no known culturing technique available for the then unknown strain of bacteria.
The origin of exposure was blow-down inhaled aerosols from an air-conditioning system. The cases indicated that smokers were at greater risk than non-smokers. Speculation as to origin was rampant, and it even included a supposed “theory” involving a relatively exotic chemical that might have been pyrolyzed while smoking cigarettes. I recall hearing a report from a U.S. Senate committee that undertook its own assessment and announced that supposed chemical cause, shortly before the true microbial agent was identified. Apparently politics and science don’t mix very well.
Retrospective investigations revealed that in fact numerous “legionnaires” cases had occurred previously and had not been identified, and that a milder form of respiratory infection called Pontiac fever was not uncommon. Many outbreaks and deaths have been reported since then, especially in hospitals. The U.S. Centers for Disease Control has estimated up to 18,000 legionellosis deaths in the U.S. each year.
What actually happens
Since 1976 it has been determined that Legionella pneumophila are fairly common soil and water bacteria and pathogenic when inhaled, not from ingestion. They grow under low nutrient warm water conditions at temperatures in the range of 25 C to 50 C. So, they can be present in warm to hot water systems, showerheads, humidifiers, misting and cooling water for air conditioning systems and hot tubs. In distribution systems and plumbing they can colonize biofilms where they may be protected from normal disinfectant residuals.
The at-risk populations are predominantly those who are elderly and also persons with impaired immune systems. Hospital environments have been the source of numerous cases of outbreaks and deaths related to Legionella. However, it is apparent that there are high-risk people in the general population; for them even a typical house or building environment could be a risk, and specific diagnoses and determinations of causal origin will be less likely.
There are water system management techniques for reducing patient risks used by many hospitals. They include monitoring their plumbing systems, additional disinfection and periodic shock disinfection or heating. Chlorine, chlorine dioxide and even peroxides and silver and copper are being used, but with some controversy for the latter two. There are several studies that indicate that systems with chloramine residuals have a much lower risk of a Legionella related outbreak than those with free chlorine residuals. The rationale is that although chloramines are less potent than free chlorine, their lower chemical reactivity allows them to more effectively penetrate biofilms that may harbor the Legionella.
Other recommendations include maintaining hot water systems above 50 C to reduce growth of the microorganisms, but the dilemma is that temperatures in the 55 C to 60 C range introduce a scalding risk, especially for children and seniors.

Moral of story
The law of unanticipated consequences is still functioning. The benefits of modern warm controlled housing environments, air conditioning and indoor hot water plumbing can have downside consequences. Even those beneficial societal technological advances can provide an opportunity for otherwise innocuous microbes to proliferate and cause disease and death.
The moral of the story is that nature is always evolving, and there are perverse unidentified microbes out there that can harm us. Water treatment to control many microorganisms, not just E. coli, is essential, and waterborne microbial disease is still, and always will be, the greatest risk from public drinking water supplies. Aging water distribution systems require aggressive rehabilitation to prevent leaks and breaks where inoculation by microorganisms and accumulation in biofilms can occur. Replacing that aging infrastructure is a much greater national priority than the hypothetical risks of trace chemical contaminants that get a lot of publicity and lead people to spend money on bottled water because they think it is safer.