The environmentally sensitive life has lots of tough, practical choices: Canola oil or not? (It depends on if the Canola is organic or GM); Top-load or front-load clothes washing machines? (Front load are more energy efficient … but more expensive); Cans or bottles? (Generally, bottles but it depends on how far they are shipped); Paper or plastic at the supermarket checkout line? (Neither. Use a strong hemp shopping bag instead); lycra or latex? (lycra … and this is a question that we hear frequently.)
Latex and lycra are both synthetic and commonly spun as a fiber that is blended with other fibers such as cotton to provide stretch and to improve the fit, comfort and freedom of movement of a garment, and to reduce creasing and wrinkling in clothing blended with natural fibers. Latex is considered by some to be a more natural fiber because it is manufactured from the milky white latex fluid collected from the sustainably grown rubber tree. But their use in clothing is not without health problems and concerns.
The Problem with Latex. Latex allergies are reported to be dramatically on the rise globally and nearing epidemic levels according to medical researchers monitoring the rise in reported latex allergy cases. Latex allergies are generally found in people with repeated and long term exposure to latex. Medical researchers report that 1% to 6% of the general population and 5% to 12% of US healthcare workers have developed latex sensitivities. Healthcare workers (including doctors, nurses, aides, dentists, dental hygienists, operating room employees, laboratory technicians, and hospital housekeeping personnel) are at greater risks of developing latex sensitivities largely because of their frequent use of latex gloves. Research surveys also estimate that 10% of rubber industry workers suffer from latex allergies.
One reason for the rise in latex allergies is because more and more people are being exposed to higher levels of latex as the use of latex and the number of products containing latex has increased hugely within the last 20 years. Latex can now be found in more than 40,000 products including automobile upholstery and tires, latex foam for pillows and mattresses, kitchen utensils and dishwashing gloves, condoms, carpet backing, balloons, baby bottle nipples and pacifiers, and many common household items. Clothing and medical care supplies are major uses of latex.
With the need to product against the rise in AIDS and other infectious diseases, the medical care industry has become a major market for latex products, especially latex gloves. More than 10 billion latex gloves are used in the U.S. each year and health care workers are especially at risk of latex allergies. Repeated exposure is necessary to develop allergies and health care professionals are regularly taking latex gloves on and off. But so are many tens of millions of other people from the kitchen to the warehouse who frequently use latex gloves to protect their hands from detergents, cleaning products and harsh chemicals.
Sensitivities to latex and latex allergies can cover a wide spectrum of symptoms that fall within three categories of reaction:
- Irritant contact dermatitis consisting of mild skin rashes and itching skin, usually on the hands from latex gloves or skin covered by latex elastic bands in undergarments and clothing;
- Delayed allergic contact dermatitis which results from exposure to chemicals added to latex during the harvesting or manufacturing processes. These chemicals can case skin reactions similar to those caused by poison ivy. Like poison ivy, the rash usually begins 24 to 48 hours after contact and may progress to oozing skin blisters in those areas of the skin that came into contact with latex.
- Latex allergies are a more serious reaction that is caused by certain proteins that occur naturally in latex. There are 57 allergenic proteins in tropical rubber latex. Reactions usually begin within minutes of exposure to latex, but they can occur hours later and have a variety of symptoms. Mild allergic reactions to latex involve skin redness, hives, or itching. More severe reactions may involve respiratory symptoms such as runny nose, sneezing, itchy eyes, scratchy throat, and asthma combined with difficult breathing, coughing spells, and wheezing. Gastrointestinal symptoms of nausea, vomiting and abdominal cramping might also occur.
Because of the growing pervasive use of latex and the increasing health concerns, latex sensitivities and latex allergies should be of concern to everyone – from the hospital operating room to the mall clothing fitting room.
The History of Latex
Latex is a natural and sustainable product that is manufactured from the milky white latex fluid collected from the rubber tree, Hevea Brasiliensis. Originally from the lower Amazon area of Brazil, the rubber tree was exported in the 1870’s by the British government to Sri Lanka and from there throughout Thailand, Indonesia, and Malaysia. Brazil is no longer a significant supplier of natural rubber latex but Thailand, Indonesia, Malaysia and Sri Lanka have become the dominant exporters of natural rubber latex growing 15.6 million acres of rubber trees which produce about 95% of the world’s natural rubber supply. A rubber tree will produce latex for at least 40 years and yield enough latex to make 10 pairs of latex gloves per week. One acre of rubber trees can yield latex for 1,500 pairs per week.
In the first half of the 1900’s, British plantation owners in Malaysia and the Dutch in Indonesia clear-cut vast areas of rainforests for rubber tree plantations. They developed bud grafting techniques that would allow high rubber-yielding trees to be cloned to produce genetically identical rubber trees in virtually unlimited and sustainable numbers. Many of these rubber tree plantations are still active and producing.
Natural latex is not made from the sap of the Hevea rubber tree which runs deeper inside the tree trunk. Natural latex runs through the rubber tree’s latex ducts found in a layer immediately outside the tree’s cambium where the sap actually flows. The rubber tree worker who makes the cuts or taps in the trunk of the tree to collect the rubber running in the tree’s latex ducts is called a “tapper” and if the tapper cuts too deep and cuts the cambium layer deeper inside the tree’s trunk, the tree can become stunted or even die. Rubber trees are generally tapped every 3 to 5 days.
The latex will drip for a few hours into a small cup before the tree heals the wound and stops the flow of latex. If the plantation manager wishes to make latex rather than hard rubber from the collected latex, the tappers will add a stabilizing agent, usually ammonia, to prevent the latex from coagulating into hard rubber.
The job of tapper is near the bottom of the worker scale. It pays little and is often filled by local women who frequently are illiterate and receive few benefits … if any. The plantation managers usually provide rather primitive and basic living arrangements to the plantation workers.
The latex rubber is then processed in different ways to manufacture products that reflect different properties – hard rubber for utensils or bottle stoppers, for example, or its elastic qualities for latex rubber gloves, rubber bands, or elastic threads used in waistbands, socks or fitted clothing.
The Problem of Proteins & Chemicals
The two primary causes of latex sensitivities and allergic reactions to latex are proteins naturally found in latex, and chemicals used during processing and manufacturing of latex products. People can get whacked by the natural proteins coming into latex and by the added chemicals going out of the manufacturing process. There are 57 allergenic proteins in tropical rubber latex and more than 200 different chemicals can be added during the manufacturing process. Some of the chemicals used to manufacture latex – such as thiurams, thioureas, carbamates and mercaptobenzothiazoles – are known allergens.
Research scientists and manufacturers have been searching for ways to reduce and eliminate the health hazards of latex by eliminating or reducing the levels of allergenic proteins. Some of their solutions to reduce the allergenic proteins in natural latex include:
- Adding proteolytic enzymes during the manufacturing process to break down the proteins;
- Centrifuging the latex compound during manufacturing to separate out proteins;
- Replace some of the chemicals known to be allergens, such as thiurams, with similar chemicals that are not allergens, such as dithiocarbamates which is not an allergen but is known to cause skin rashes and can cause abnormal thyroid functioning;
- Dip the processed latex in a chlorinated solutions such as sodium hypochlorite acidified with hydrochloric acid.
Many of these solutions also tend to reduce the tensile strength and elasticity of natural latex.
Botanists have also investigated collecting latex from other latex-producing trees, shrubs and plants but none have been found to equal the latex rubber tree. Scientists have also worked to develop synthetic latex that would still have the elasticity, impermeability, and tensile strength of natural latex.
The Big BreakThrough
For the garment industry, the big breakthrough in an alternative to latex fibers came in 1959 when Joseph Shivers, a DuPont chemist, cooked up the first batch of spandex. Spandex came to revolutionize the garment industry and swimsuits have never been the same since. [It is rumored that spandex has surpassed corn, wheat and soybeans as our largest export to Japan.] Originally called “Fiber K”, DuPont christened their new fiber “spandex” which is an anagram of “expands”. Spandex is the generic name that has been trademarked as Lycra®.
Spandex, also known as elastane in most of the world outside of North American and Australia, has many characteristics that have ingratiated it into the fashion industry. Spandex:
- can stretch more than 500% without breaking;
- can be repeatedly stretched and always return to its original shape without stretching out, bagging or sagging;
- is stronger than latex rubber fibers;
- is comfortable, soft, smooth, and supple;
- is resistant to body oils, perspiration, lotions, and detergents;
- blends well with other fabrics such as cotton, hemp, wool, silk, and linen;
- does not contain any protein allergens;
- is abrasion resistant and will not pill or create static.
When chemists think of spandex / Lycra®, they do not envision sleek swimsuits, form-fitting sports wear, elegantly enticing evening wear, or even enhancing undergarments. To the chemist, spandex fosters images of a long-chain synthetic polymer comprised of at least 85% segmented polyurethane in a segmented block copolymer containing long, randomly coiled, liquid, soft segments that move to a more linear, lower entropy, structure. These fibers exploit the high crystallinity and hardness of polyurethane segments, yet remain soft and rubbery due to alternating segments of polyethylene glycol.
Because it is a superior fiber over latex and it does not contain allergen proteins, Lycra has largely displaced latex as a fiber in clothing except in waistbands and other elastic bands sometimes found in clothing such as straps in swimsuits and undergarments. Pre-made elastic bands of latex are cheaper to sew into clothing than knitted-in bands made of Lycra. As a general rule for the consumer, sewn-in elastic bands are more likely to be made of latex and knitted-in elastic bands are more likely to be made of Lycra. Some manufacturers wrap their latex waistbands in cloth to keep them from touching sensitive skin around waists and wrists. Most, but not all, manufacturers of natural and organic clothing have realized the health concerns of using latex and replaced latex with Lycra in their garments. The trend for all manufacturers is to replace latex fibers with Lycra fibers. Some manufacturers are doing it for consumer health concerns, some are doing it because the cost of Lycra fibers is coming down and approaching that of latex, and some are doing it because Lycra is more durable and can be spun into finer fibers with superior properties. If you have doubts or questions if a garment contains latex, ask your retailer.
The Problem with Lycra. Of course, spandex / Lycra also have their own health and sensitivity concerns. Cases of dermatitis, skin irritations and rashes have been traced back to garments containing spandex / Lycra. Some people with chemical sensitivities are unable to wear clothing containing fabrics blended with Lycra. The spandex / Lycra polymer has not been proven to be a skin sensitizer and most of skin irritation problems are probably caused by chemicals added to spandex / Lycra fibers during the finishing process. Fiber, fabric and garment finishing processes can vary greatly from manufacturer to manufacturer. Organic and natural clothing manufacturers try to keep their clothing as healthy, environmentally-friendly and free from toxic chemicals as possible. But, as we’ve seen with low-impact dyes, people have varying degrees of health sensitivities to chemicals that are benign to most people. Many people with chemical sensitivities are able to wear undergarments containing elastic bands made from Lycra provided that the elastic band is wrapped in organic cotton.
Once again, the best defense is to become an informed and questioning consumer.
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