Frequently Asked Questions.

What is Natural Rubber Latex (NRL)?

Where is Natural Rubber Latex produced?

What makes Vytex™ NRL unique?

Where is Vytex NRL produced?

What are latex allergies? Who is at risk?

What is the accepted method for Natural Rubber Latex protein testing?

Is there a particular protein level that can cause an allergic reaction?

Why is a reduced level of total allergenic protein important?

What is the ASTM D 6499-07 ELISA Standard Test Method?

What are the limitations of the Modified Lowry and ELISA Test Methods?

Can I compare the test results for the Modified Lowry and ELISA Inhibition Assay tests?

Why does Vystar™ favor the ELISA method over the Modified Lowry method for testing protein levels?

Who does Vystar Use for Protein Testing?

What is the FITkit Test?

What are the protein differences between Vytex NRL and Hevea natural rubber latex?

What products can Vytex NRL be used in place of Hevea natural rubber latex?

Are any changes necessary to my manufacturing processes to use Vytex NRL?

Are storage requirements different for Vytex NRL?

Can I use the same Hevea natural rubber latex compounding chemicals with Vytex NRL?

Can leaching time be reduced for products made from Vytex NRL?

What are the end physical performance differences between Vytex NRL and Hevea natural rubber latex?

How do products made from Vytex NRL behave upon aging?

There has been a lot of news recently about phthalates. What are phthalates and are they in Vytex NRL?

I am a manufacturer and I would like more information on how my product could use Vytex NRL?

What is Natural Rubber Latex (NRL)?
Latex is the protective fluid contained in tissue beneath the bark of the rubber tree, Hevea brasiliensis. Natural rubber latex (NRL) is a cloudy white liquid collected by cutting a thin strip of bark from the tree and allowing the latex to be secreted into a collection cup over a period of several hours. After collection the latex is treated with a preservative, typically ammonia, to prevent coagulation and then is transported to a processing facility for concentrating and compounding. The composition of natural rubber latex consists of approximately 30-40% rubber particles, 55-65% water and small amounts of protein and other substances.



Where is Natural Rubber Latex produced?
Today, more than 90% of the natural rubber supply comes from Southeast Asia in places such as Thailand, Malaysia and Vietnam. As rubber trees require a hot, damp climate, they grow only in the "Rubber Belt", an equatorial zone that stretches around the world. In 1876, the English, in recognition of the difficulties of securing quality rubber from the jungle, hit upon the idea of growing rubber on plantations. From their efforts, the cultivated rubber tree plantations of Southeast Asia and parts of Africa have developed.



What makes Vytex™ NRL unique?
Vytex NRL is a chemically modified natural rubber latex to reduce its allergenic properties. The patented protein removal process is achieved by the introduction of Aluminum hydroxide (Al(OH)3, a well known protein binding chemical, to the NRL source material. Al(OH)3 is an amphoteric substance, meaning it can react as either an acid or base and readily shares electrons with proteins. Under certain conditions, Al(OH)3 produces protein complexes that are removed from the Vytex NRL liquid solution using existing industry practices. Vytex NRL can be used as a standard source material for many product applications and wherever Hevea natural rubber latex is used.



Where is Vytex NRL produced?
Vytex NRL is produced at the latex processor level and can be easily integrated without the capital need for special or additional equipment.



What are latex allergies? Who is at risk?
Latex allergy is an allergic reaction to substances in natural latex. There are three types of latex reactions;
  • Irritant contact dermatitis
  • Allergic contact dermatitis
  • Immediate allergic reaction (latex hypersensitivity)
    It is estimated that 17% of American healthcare workers and up to 73% or more of frequently exposed patients, such as those with spina bifida, have become sensitized to the antigenic latex proteins. Approximately 3% of the general population have allergic reaction to NRL.



    What is the accepted method for Natural Rubber Latex protein testing?
    There are several test methods available to evaluate protein in natural rubber latex products. Currently, the Food and Drug Administration (FDA) accepts only the Modified Lowry method developed by the American Society for Testing and Materials (ASTM). This method, referred to as ASTM D 5712-05, was approved in April 1995 and updated in 2005. The test measures the total water extractable protein on a latex product including, but not limited to, any milk protein (used by some manufacturers), enzymes, natural rubber latex proteins and any other types of protein present.



    Is there a particular protein level that can cause an allergic reaction?
    Similar with most allergies, researchers have not been able to determine the exact level of natural rubber latex protein exposure, or how many exposures, will cause an individual to become allergic and to begin expressing symptoms.

    There is scientific consensus that reduced allergenic protein levels will lower the potential for both sensitization of non-sensitized genetically susceptible individuals and allergic reactions in sensitized individuals.



    Why is a reduced level of total allergenic protein important?
    Scientific studies provide evidence that the greater the overall exposure to an allergy-causing substance, the greater the risk of sensitization in genetically predisposed individuals. Reduced exposure to natural rubber latex allergenic proteins has been reported in the literature to be associated with decreased allergenic response.



    What is the ASTM D 6499-07 ELISA Standard Test Method?
    The ASTM D 6499-07 Standard Test Method for the Immunological Measurement of Antigenic Protein in Natural Rubber and its Products ELISA Inhibition Assay. This assay uses an Inhibition ELISA to quantitate antigenic latex protein in product extracts. In an Inhibition ELISA, soluble antigens in the extract compete for binding to specific anti-latex antibodies and block antibody binding to latex antigen immobilized on the surface of the assay plate. Results are usually expressed in micrograms of antigenic protein per gram (ug/g) or square decimeter (ug/dm2) (a measurement of surface area).



    What are the limitations of the Modified Lowry and ELISA Test Methods?
    Vytex NRL is a new product that has been chemically modified to reduce its allergenic properties. It has been thoroughly tested during development using both the Modified Lowry and ELISA test methods. The Modified Lowry test has well known weaknesses and is particularly vulnerable to interfering substances and subject to variability. The Modified Lowry test is approximately 150 times less sensitive than immunochemical methods for antigenic protein detection such as the ELISA method. The ELISA test method measures antigenic protein and Vytex NRL in (un-leached) film samples after six months storage consistently yield less than 10 ug/g of antigenic protein. The Vystar technical team continues to investigate all protein test methods to ensure the low antigenic properties of Vytex NRL.



    Can I compare the test results for the Modified Lowry and ELISA Inhibition Assay tests?
    No. The ELISA Inhibition assay is a method used to test for antigenic latex proteins. The Modified Lowry assay is a method used to test for total water-extractable protein. Because each test method determines a different substance (total vs. antigenic protein) and employs different procedures, the end results cannot and should not be compared.



    Why does Vystar™ favor the ELISA method over the Modified Lowry method for testing protein levels?
    There are over a hundred different proteins in latex with only a small number of these proteins capable of causing an immunologic reaction, referred to as antigenic proteins. The modified Lowry (ASTM D 5712-05) detects total proteins and is approximately 150 times less sensitive than immunochemical (ELISA) method which detects antigenic proteins. Testing for antigenic proteins capable of triggering an immunologic reaction will offer a better assessment of the efficacy of the product.



    Who does Vystar Use for Protein Testing?
    Vytex NRL and products made with Vytex NRL have been tested at The Donald Guthrie Foundation Education Research, LEAP Testing Service, a highly respected independent laboratory located in Sayre, PA. Vystar has maintained a 10 year working relationship with Guthrie and, to date, has tested over 500 samples using the ELISA and Modified Lowry test methods.



    What is the FITkit Test?
    FITkitŪ, a trade mark of Quattromed Ltd., is a relatively new testing methodology (2001) that measures individual NRL allergens. It is currently not supported by the FDA and has not been validated by the American Society for Testing Methods (ASTM).

    To date, we have done limited testing using FITkit. We will incorporate FITkit into our testing protocols at the time it becomes an established ASTM standard.



    What are the protein differences between Vytex NRL and Hevea natural rubber latex?
    Vytex NRL (un-leached) film samples have been thoroughly analyzed during our development phase. Over 500 sample films and products made with Vytex NRL have been independently tested for protein levels during development. Protein testing using the Modified Lowry and ELISA methods occurred at three time intervals: 1) immediately after production, 2) after 21 days of storage and, 3) after 6 months of storage.

    Test results during all phases of protein testing generated less than 10 ug/g of antigenic protein using the ELISA protein test method for un-leached film samples. Products made from Vytex NRL under similar conditions used for Hevea natural rubber latex production frequently exhibit less than 0.2 ug/g of antigenic protein. Overall, Vytex NRL typically has 90% fewer antigenic proteins than Hevea natural rubber latex.



    What products can Vytex NRL be used in place of Hevea natural rubber latex?
    Vytex NRL has been designed as a standard source material that can be used in place of Hevea natural rubber latex. There are over 40,000 commercially available products made from Hevea natural rubber latex. These products include medical goods such as gloves, breather bags, probe covers, tubing; consumer products like condoms and balloons, and commercial products such as cold seal and pressure sensitive adhesives. Vytex NRL has been successfully trialed in each of these product applications potentially offering end-users the performance they expect from NRL with reduced antigenic protein values.



    Are any changes necessary to my manufacturing processes to use Vytex NRL?
    No. The production of Vytex NRL removes proteins and other unwanted impurities from the liquid latex. Since a significant amount of proteins are removed during Vytex NRL processing, manufacturers seeking to reduce their protein leaching times may now have an opportunity to do so with the use of low protein Vytex NRL.



    Are storage requirements different for Vytex NRL?
    No. However since Vytex NRL has been specially processed to remove proteins and other unwanted impurities, we recommend that existing storage tanks be thoroughly cleaned prior to storage and use of Vytex NRL.



    Can I use the same Hevea natural rubber latex compounding chemicals with Vytex NRL?
    Vytex NRL has very similar properties to Hevea natural rubber latex and should be compatible with current compound formulas. The Vystar technical team is available to assist manufacturers with the integration of Vytex NRL within their current manufacturing processes.



    Can leaching time be reduced for products made from Vytex NRL?
    Since Vytex NRL starts with low protein levels in liquid latex, it can be hypothesized that extensive post leaching times for protein reduction can be minimized. Every manufacturer's production process is unique; please consult with the Vystar technical team for your particular application.



    What are the end physical performance differences between Vytex NRL and Hevea natural rubber latex?
    The physical properties of products made from Vytex NRL under similar conditions and processes uses for Hevea natural rubber latex are within the standard industry specifications for natural rubber products Type 1 classification. Vytex NRL typically exhibits a lower initial modulus and good resistance to aging compared to products made from Hevea natural rubber latex.



    How do products made from Vytex NRL behave upon aging?
    Vytex NRL is 'passivated' during treatment which reduces its sensitivity to UV and IR frequencies. Vytex NRL maintains its strength during artificial heat aging which enhances the barrier protection properties over Hevea natural rubber latex. Our test results indicated condoms made with Vytex NRL were 30% stronger than condoms made from Hevea natural rubber latex when aged for 100°C for 22 hours and exam gloves made with Vytex NRL aged under similar conditions had a 32% lower initial modulus compared Hevea natural rubber latex. The Al(OH)3 removes and deactivates those molecular species vulnerable to free radical breakdown.



    There has been a lot of news recently about phthalates. What are phthalates and are they in Vytex NRL?
    Phthalates, or phthalate esters, are a group of chemical compounds that are mainly used as plasticizers (substances added to plastics to increase their flexibility). They are primarily used to turn vinyl from a hard plastic into a flexible plastic. Vytex NRL does not contain any phthalates.



    I am a manufacturer and I would like more information on how my product could use Vytex NRL?
    Please contact us by email or by calling Vystar Corporation at (770) 965-0383. We will be happy to provide additional information or any technical support you may need.


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