A DANGEROUS OCCUPATION: Making Rayon                                                    

For well over a century, viscose rayon has been used to make clothes, tires, cellophane and everyday kitchen sponges.

What makes regular pulp different from dissolving pulp from wood which is the substance needed to make rayon is an extra chemical process that removes hemicellulose. It is a weaker polysaccharide inside the biological composition of the individual pulp cells. By removing these weaker elements, this process ensures that the pulp has higher cellulose content that is usually around 92 per cent. The result is regarded in the pulp and paper industry as “specialty cellulose.

This substance is then pressurized and put through a screening process where large fragments, knots, dirt and other debris is removed. Once the rejected materials are removed, what remains is pulp. The pulp is then washed to remove any further debris, bleached to remove its colour and then steam-dried, packaged in the form of sheets.

What makes regular pulp different from dissolving pulp (the substance needed to make rayon) is an extra chemical process that removes hemicellulose – a weaker polysaccharide inside the biological composition of the individual pulp cells. By removing these weaker elements, this process ensures that the pulp has higher cellulose content – usually around 92 per cent – so much so that it is regarded in the pulp and paper industry as “specialty cellulose. ”Its microbiological strength is what makes it perfect for creating rayon.

To create the fiber, the cellulose has to be put through a series of chemical and physical procedures. First, the cellulose is dissolved in sodium hydroxide (also known as caustic soda) then the solution is pressed between rollers to remove excess liquid. The pressed sheets are crumbled or shredded to produce what is known as “white crumb.”

The white crumb is aged by exposing it to oxygen, then mixed with carbon disulfide in vats under a controlled temperature – usually around 20 to 30°C. This changes the chemical makeup of the cellulose mixture and results in a product called cellulose xanathate, or “yellow crumb.”

The yellow crumb is then dissolved in a caustic solution and forms yet another product called “viscose” because of its very high resistance to force – or – viscosity. The viscose is set to stand for a period of time to “ripen,” allowing the cellulose to regenerate when it’s finally formed into a filament.

After it is ripened, the viscose is filtered to remove any un-dissolved particles, degassed to remove any bubbles of air and put through a spinneret – a multi-pored device that forms numerous individual filaments. As the viscose exits the spinneret, it lands in a bath of sulfuric acid resulting in the formation of rayon filaments. The rayon filaments are then stretched to straighten out the fibers, washed to remove any residue chemicals and cut into spools and – depending on the client’s wishes – dyed. Now the packages of the finished product are to be shipped to its customers.

So, what is so dangerous about this during the manufacturing of rayon and the cellophane?

The making of rayon is an industrial hazard whose egregious history ranks up there with asbestos, lead and mercury. The manufacturing of viscose rayon serves as a death sentence for many industry workers working in the plants manufacturing rayon. 

There was a famous rubber factory where they put bars on the second story windows because so many workers had a tendency to jump out and kill themselves rather than die slowly from the effects from the disclosure of the toxic fumes.

The key ingredient in the making of viscose is a molecule called carbon disulfide — a molecule so insidiously toxic that it devastated the minds and bodies of factory workers for more than a century. Carbon disulfide can exist in air as vapor. The way to protect workers is to issue them masks. Alas, many of the manufactures in China, Japan and other countries prefer not to go to that expense. Rayon isny manufactured in the US or in Canada and other countries so that problem doesn't exist in those countries.

It is pretty easy to recognize the toxic effects early on because it makes workers insane. It has been found that about 30 per cent of the workers that were investigated showed signs of serious poisoning.

Several epidemiology studies have reported increased mortality among workers in viscose rayon plants who were occupationally exposed to carbon disulfide as well as other chemicals.

Deaths have also been reported in a community in India following an accidental release of large amounts of carbon disulfide, hydrogen sulfide, and sulfuric acid from a viscose rayon plant. However, no definitive or consistent conclusions can be drawn from these studies because of concomitant exposure to other chemicals plus uncertainty about exposure concentrations, and the likelihood of multiple routes of exposure.

In a 10-year (1975-1985) epidemiological study of 251 workers exposed to carbon disulfide and 124 controls in two viscose rayon factories in Czechoslovakia, increased in total and cardiovascular mortality were noted in spinners exposed to high levels of carbon disulfide.  Although associated levels of exposure were not quantified for this particular group, the study authors of the report estimated that exposures ranged from less than 9.6 to 48 ppm. However, insufficient data were provided to fully support their conclusions. An approximately 15% increase in deaths resulting from circulatory disease was observed among Dutch viscose rayon workers exposed to carbon disulfide concentrations which were described as “at least 7 ppm, and possibly higher” The increased risk of dying from circulatory disease was greatest 20-30 years after the start of the exposure.

Following an accident involving a railroad car, 27 individuals were exposed via inhalation to an unspecified concentration of carbon disulfide. Subtle and transient changes in pulmonary function were manifested as reduced vital capacity and decreased partial pressure of arterial oxygen Dyspnea (shortness of breath) was reported in 77 of the 123 persons following an accidental release of large amounts of carbon disulfide, hydrogen sulfide, and sulfuric acid from a viscose rayon plant in India.

The manufacturers from China and Japan say that the fabric continues to this day to be "greenwashed" as an eco-friendly product. They omit entirely the fact that you can't make the product without this toxic chemical. So the manufacturers are lying to cover-up the fact that many pf their employees are suffering from this deadly toxic.

As early as 1963, Lenzing started recycling the chemicals from pulp production after the company switched from the calcium bisulphite method to an environmentally friendly magnesium bisulphite method.  However, there are many manufacturers of rayon.  Even with the advancements that have been made over time, most rayon manufacturing processes in use today are not considered environmentally friendly.

Lyocell manufacturing, and Tencel in particular, is an extremely environmentally friendly process and the most-friendly of these three fibers. The revolutionary aspect of Tencel manufacturing is the recovery and reuse of up to 99.8% of the solvent and the remaining emissions are broken down in biological water treatment plants. In fact, the solvent is not acidic. The harmlessness of the solvent has been proven in dermatological and toxicological tests. One can put their bare hand in the solvent without harm (although it’s probably not advisable to leave it there). Also, no toxic substances remain in the fiber.

The other manufacturers have to an environmental friendly process if they want t save the wellbeing of their workers.

Consumers aren't affected since there are no toxic vapors coming from the finished products. For this reason, there's not very much impetus for outrage in countries that have this problem if it's just the workers in the factories making the finished product who suffer especially when the workers are not in the US, Canada and other westernized countries. Occupational health and multinational corporations in other countries who manufacture Rayon and other similar products have been aware of the dangers, but motivated by indifference and that the factories make huge profits—both have failed to act.