QUIMICA Y EL LIDER: HOW TO FORMULATE INSECT REPELLENT

martes, 26 de agosto de 2008

HOW TO FORMULATE INSECT REPELLENT

An insect repellent is usually a liquid that is used on the skin or clothes to discourage the climbing or landing of insects like fleas, flies, mosquitoes and ticks on the surface.
Normally repellents work by masking carbon dioxide, lactic acid and sweat odors that are emitted by the human body and by having a specific scent that insects avoid.
The best proven chemical repellent is DEET ( N,N-Diethyl-m-toluamide; C12H17NO).
A concentration of 0.1 grams is enough to act on a 72 square inch area of skin.
Formulations are basically based on a 5 to 25 % concentration.
A typical formula contains: 10 % DEET, 40 % Alcohol, 0.5 % Carbomer, 48.5 % Water and 1 % of a 50% solution of TEA. Simply add the carbomer to the Alcohol and DEET and then add slowly the water and finally the TEA.
A natural repellent can be made by using Geranium oil, Citronella oil, Lemon Eucalyptus oil and also Vitamin E has proven to be effective in an oil suspension.

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GREEN CHEMICALS

The Green Seal certification is granted by the organization with that name and has a great number of members contributing with the requirements to pass a raw material or a chemical product as "green". Generally for a material to be green, has to comply with a series of characteristics like: near neutral pH, low volatility, non combustible, non toxic to aquatic life, be biodegradable as measured by oxygen demand in accordance with the OECD definition.
Also the materials have to meet with toxicity and health requirements regarding inhalation, dermal and eye contact. There is also a specific list of materials that are prohibited or restricted from formulations, like ozone-depleting compounds and alkylphenol ethoxylates amongst others. Please go to http://www.greenseal.com/ for complete information on their requirements.
For information on current issues regarding green chemicals, see the blog from the Journalist Doris De Guzman, in the ICIS at: http://www.icis.com/blogs/green-chemicals/.
Certification is an important — and confusing — aspect of green cleaning. Third-party certification is available for products that meet standards set by Green Seal, EcoLogo, Energy Star, the Carpet & Rug Institute and others.
Manufacturers can also hire independent labs to determine whether a product is environmentally preferable and then place the manufacturer’s own eco-logo on the product; this is called self-certification. Finally, some manufacturers label a product with words like “sustainable,” “green,” or “earth friendly” without any third-party verification.
“The fact that there is not a single authoritative standard to go by adds to the confusion,” says Steven L. Mack M.Ed., director of buildings and grounds service for Ohio University, Athens, Ohio.
In www.happi.com of June 2008 edition, there is a report of Natural formulating markets that also emphasises the fact that registration of "green formulas" is very confused at present, due to lack of direction and unification of criteria and that some governmental instittion (in my opinion the EPA) should take part in this very important issue.

QUALITY CERTIFICATIONS

What Is ISO 14001 And Should I Care?
Increased awareness of sustainable development gives environmentally credible companies a competitive edge in national and international markets. A certified Environmental Management System proves that your business is taking active steps to fulfill your responsibility.
What Occupational Health and Safety Assessment Series (OHSAS 18001) and Should I Care?
An OHSMS promotes a safe and healthy working environment by providing a framework that allows your organization to consistently identify and control its health and safety risks, reduce the potential for accidents, aid legislative compliance and improve overall performance.
OHSAS 18001 is the internationally recognized assessment specification for occupational health and safety management systems. It was developed by a selection of leading trade bodies, international standards and certification bodies to address a gap where no third-party certifiable international standard exists.
What Is ISO 9000 And Should I Care?
ISO 9000 consists of a series of Quality Management System standards that are designed to facilitate and enable consistency of a product or service and thereby ensure that customer requirements are met or exceeded. They can be applied in any manufacturing industry or service sector.
The value of certification to customers is evident, but the quality of the certificate is also important. All certificates are not equal.

VISGAGE POCKET VISCOSITY COMPARATOR

This is another simple viscosimeter , to check relative viscosity of oils (from light motor oils to heavy machinery and gear oils)and can be used on site without the use of stopwatch or thermometer. It consists of a plate and a spreading device, see details at : http://www.visgage.com/
The latest version for high viscosity liquids is the Efflux test Cup, that can be used for hot fluids, up to 50000 cps. The cup has internal pins to measure laminar flow instead of transitional flow out of the cup's botom and has different hole sizes to handle various viscosity ranges. See www.viscosity.com for more details.

HOW TO SELECT THE BEST SOLVENT FOR A CLEANING JOB

To clean heavy grease, resins, tar or heavy hydrocarbon residues, a solvent based cleaner is necessary for a fast and effective job. To select the appropriate solvent or solvent combination, there is a fundamental list of characteristics to check:
1-Flash Point: the highest the flash point, the lower the risk of ignition. Also if the flash point is above 140 F, the product can be shipped as non hazardous.
2-Toxicity: important to know if the solvent will be used outside or in enclosed areas and check the allowed exposure levels from the MSDS.
3-Odor: again, will it be used in enclosed areas, will you need an extraction hood, is the odor irritating?
4-Evaporation rate: if the evaporation rate is too slow it may leave residue or too slow drying, if too fast may have not enough time for cleaning.
5-Solvency or cleaning power:checking the Kauri Butanol
is an indication, the higher value the better.
6-What is the cost?: this might be a limitating factor in using the selected solvent in your product.
7-VOC: the volatile organic compound classification from a regulatory standpoint, may limit the use of the solvent.
8-Compatibility: with other components of the formulation. 9-Biodegradability: in water and land.

NOTAS DE UTILIDAD....COMO AGREGAR FRAGANCIA AL CLORO

HAY CIERTAS FRAGANCIAS QUE SON COMPATIBLES CON EL HIPOCHLORITO DE SODIO. LA MAYORIA DESACTIVAN EL CLORO O LO LIBERAN DE SOLUCION. SIN EMBARGO EL USO DE POCAS CANTIDADES DE FRAGANCIA PUEDE SER EMUSIONADA SIN SACRIFICAR MUCHO LA ESTABILIDAD. EN ESPECIAL POCA CANTIDAD DE FRAGANCIA DE LIMON O DE PINO LE DAN UNA BUENA CONNOTACION Y DEBEN SER AGRAGADAS, LUEGO DE AGREGAR UNA CANTIDAD SIMILAR DE LAURIL SULFATO DE SODIO CON OXIDOS DE AMINAS COMO EMULSIONANTES. NO MEZCLE LOS SURFACTANTES CON LA FRAGANCIA PREVIO A INCORPORARSE.

HLB: HYDROPHILIC / LIPOPHILIC BALANCE

This balance will determine a surfactant's relative solubility in water or oil.
The range of values for the HBL will determine its application and performance:
VALUE APPLICATION
3.5-6 Water in oil emulsifier
7-9 Wetting agent
8-18 Oil in Water emulsifier
13-15 Detergent
15-18 Solubilizer and microemulsions

The HLB value in the surfactants is given by the extent of etoxilation which results from the reaction of linear or aromatic alcohols with molecules of ethylene oxide.
Thus as a guide, 1-3 moles of etoxilation will give a value for the HLB round 3.5-6; 4-6 moles EO will result in a 7-9 HLB; 7-12 moles EO, 10-15 HLB; over 12 moles EO will give an HLB between 15-18.