CPWR – Center for Construction Research and Training
This material is supported in part with funds from the National Institute for Occupational Safety and Health (NIOSH) through CPWR – Center for Construction Research and Training to a consortium of CPWR, the Operative Plasterers & Cement Masons International Association, and FOF Communications. Researched, written, and produced by FOF Communications.
The material does not necessarily reflect the views or policies of NIOSH. Mention of trade names, commercial products or organizations does not imply endorsement by NIOSH, the U.S. Government, CPWR, OPCMIA, or FOF Communications.
The Occupational Safety and Health Act of 1970 makes the employer responsible for providing a safe and healthful workplace that is free of recognized hazards.
© 1999, 2000 FOF Communications
Table of Contents
Skin problems from cement are widespread. Unfortunately, problems are often tolerated as part of the price of the work in some trades. Our tolerance permits the high rates of occupational skin problems in the United States to continue. A change in attitude is needed.
As a safety & health practitioner, you may find that you too hold many of the more traditional assumptions about how to prevent occupational skin problems.
If you believe skin protection is fundamentally a matter of getting workers into the proper gloves, then you will find much in this guide that is innovative and thought-provoking.
One of your challenges is to convince cement products workers that it is possible for them to prevent occupational skin problems. But first, they - and you--must recognize when skin problems exist. Often, rashes and other symptoms are downplayed or overlooked as a prelude to chronic disease.
A central challenge
is motivation. Here the health impact on family members and partners 1
may be key. Workers are motivated to take protective measures when they
believe it protects their children. 2 Other key motivations
include comfort and availability and a belief that employers, fellow workers,
and union representatives support their actions.2
As a safety & health practitioner, you can take many actions in support of worker protection. In addition to educating workers, you can educate employers. You can work to create an environment in which the individual workers decision to adopt protection is reinforced by social influences and in which protections are readily available and easy to use.
As a safety &
health practitioner, you can help workers choose the right protective
measures, you can convince employers to take the best protective actions,
and you can keep both groups continually motivated so that incremental
progress will be made.
What Problems Does Cement Cause?
Four types of skin
problems happen most often among cement products workers:
Skin problems can be mild and short-lived or severe, persistent, and disabling. Problems can happen after single or multiple exposures. It is difficult, if not impossible, to predict who will get skin problems based on experience or on medical tests.
Skin or Irritation ( Mild ICD)
Dry skin or irritation
may include scaling, it chiness, burning, and redness.
Dry skin may also
be called xerosis. Portland cement exposure can lead directly to dry skin
Contact Dermatitis (ICD)
dermatitis (ICD) can be acute or chronic. Symptoms may include stinging,
pain, itching, blisters, rash, dead skin, scabs, scaling, fissures, redness,
swelling, bumps, and watery discharge. Sometimes irritated skin may become
infected. Exposure to portland cement can lead directly to ICD without
first causing dry skin.
Alkalinity is essential in the development of irritant contact dermatitis from portland cement. 3 Cement makes the skins barrier layer more alkaline and permeable. As the barrier layer becomes permeable, repeated contact with abrasive particles in cement products may contribute to ICD and ACD.
It can be difficult to recognize ICD by its appearance or morphology alone.4 Proper diagnosis of work-related ICD requires a complete work history and a physical examination.
Contact Dermatitis (ACD)
Allergic contact dermatitis (ACD) is an immune response. It is like other allergies but it involves the skin. ACD includes many of the same symptoms as ICD.
portland cement contains metals or other chemicals which are sensitizers,
or allergens. Foremost among them is hexavalent chromium (Cr
) . Others may be present in admixtures: accelerators, water reducers,
superplasticizers, retardants, air entraining agents, or polymer-modified
Sensitivity to Cr 6+ and ACD may slowly develop in Portland cement products workers after many years of exposure to soluble chromium in cement. It is even possible to develop ACD up to five years after exposure to Portland cement has ended.5
ACD can develop without any warnings, such as local irritation. ACD is difficult to cure. The allergy may last a lifetime, with symptoms recurring after each exposure.
Burns (Cement Burns)
(cement burns) are chemical burns. Second or third degree burns may occur
after relatively short exposures to fresh mortar, concrete, grout , and
other Portland cement products. Cement burns look like other burns. They
produce blisters, dead or hardened skin, or black or green skin. Cement
burns can lead to allergic dermatitis. In addition, chromate sensitivity
can exacerbate the severity of cement burns.
The occurrence of alkaline burns from Portland cement is well documented. No official data exist on the annual number of cases. A statistically valid 1997 survey found cement burns among 35% of apprentice concrete masons nationwide.6
In severe cases, these burns may extend to the bone causing disfiguring scars, even disability. Some may require skin grafts.
Refer cement burns to a medical specialist without delay. When a worker feels a cement burn, much damage already has been done and further damage can develop unless medical treatment is received.
Worry About Portland Cement ?
Ted Jason' s problems are not uncommon. You probably know many workers with skin problems from cement. Portland cement is estimated to account for 25% or more of all work-related skin problems worldwide. 7
Reported lost work
days for skin problems in U.S. masonry trades are 2.5 times the national
lose time at 7 times the national average. Concrete workers report 4 times
more lost work days for skin problems than do all construction workers.8
Some 5 to 15% of workers coming into contact with Portland cement that contains hexavalent chromium may suffer allergic contact dermatitis, a rate as high as 25 times that of the general population.9 This dermatitis may persist in 20 to 40% of workers without further exposures, even after they leave the trade.
Experts agree that reported lost time is just the small tip of a very large iceberg of skin disease. One indication of how prevalent skin problems are comes from a statistically valid survey of apprentice cement masons.
In 1997, 442 apprentices were surveyed using a questionnaire derived from one used by NIOSH.6 The response rat e was 100%. The mean age of t he surveyed apprentices was 27; the most frequent age was 20. The mean number of years in the industry was 3.3.
A surprising 71%
of the apprentices reported one or more skin problems in the previous
12 months, including rashes, bumps, blisters, fissures, scaling, redness,
oozing, burning, and pain. Only 29% reported no skin problems.
Only 7% of those reporting skin problems reported lost time or physician visits for their problems. 93% of the apprentices with skin problems continued to work without seeking medical treatment setting themselves up for lifelong health problems. (Also see Halbert .9) Asked whether they had had eczema or dermatitis at any time during their careers, only 3% of surveyed apprentices said yes, indicating possible lack of medical diagnosis.
Studies show poor
prognosis for complete clearing of occupational contact dermatitis, once
established. Recent studies show that 30-55% of patients have continued
problems with the skin disease at follup up. 10,11,12,34
Skin has two primary
layers. Together, both are less than 1/ 8-inch thick.
The dermis and epidermis contain oil glands, hair follicles, and sweat glandsall are like tiny channels through the skin letting in some foreign substances. Skin also contains blood vessels. Some chemicals can penetrate the skin and enter the bloodstream.
The layer of dead surface cells at the outer epidermis is the stratum corneum. Leading researchers now call it a biosensor that regulates the epidermal lipid and DNA-metabolic responses to a variety of insults. 13 The stratum corneum is a "thin membrane of keratimized corneocytes in a 'brick and mortar' structure."14 It has the most mechanical strength of all the layers of the epidermis.4
The old model of skin disease assumed that skin responds directly to external insults. The response included conditions like inflammation, rashes, or even scar tissue.
Scientists can now detect skin function at the molecular level due to advances in bioengineering technologies.
The Signal Cascade
The resulting new
model shows that external insult triggers a cascade
of molecular signals at the outer layer of the stratum corneum (permeability
barrier) . This causes release of enzymes and formation of proteins
and ultimately may lead to the trapping of inflammatory disease-specific
cells in the dermis.13 The outcome is repair of the injured
barrier and/or symptoms of various skin disorders.15
So the permeability barrier plays a critical role in maintenance of healthy skin.14 Any insult that disrupts the barrier injures the epidermis. Disruptions of the permeability barrier produce a response of recovery or repair. This may lead to normalization of barrier function within hours to days, depending on age and severity and persistence of the insult.13,15
When barrier disruption
is persistent , these processes become chronic. In some individuals, the
repair response compensates for insults and produces 'hardening.' Hardening
is a state of accommodation.
Workers whose skin
has hardened may experience less irritation. However, epidermal hyperplasia
and inflammation persist , 15 leaving skin at risk of disease.
Others may never accommodate to irritants and never experience hardening.'
The role of pH in barrier maintenance and repair is discussed further in Chapter 4.
Initiate Skin Problems?
Skin may be affected
by one or more insults:
Worksite materials can start skin problems. Some materials insult and injure skin. Some also pass through it to the bloodstream.
Portland cement is very alkaline (caustic) when wet so it affects skin surface pH. The moisture in eyes, mucus, and sweaty skin can contribute water to dry cement, releasing its causticity. Portland cement is hygroscopic so it draws moisture from skin. Cement products are abrasive and physically damage the skin surface, making it a less effective barrier against chemicals. These factors allow cement to cause dry skin and irritant contact dermatitis.
Sensitizers in workplace materials may cause allergic responses in some workers. The reaction may be local or widespread. Sensitization is an immune response. The immune system fights a foreign substance. Usually, the material causes no change on first contact. Once a person is sensitized, small amounts trigger a strong reaction. Many people cannot tolerate any further exposure.
Possible sensitizers used by cement products workers include: hexavalent chromium (Cr6+) in cement, chemical admixtures in concrete, epoxies, additives in rubber gloves, and other trace metals in cement.
Hexavalent chromium (Cr6+) is rated as a strong to extreme sensitizer. It is an important cause of allergic contact dermatitis. Cement's alkalinity increases skin absorption of this soluble chromate. Some studies show that Cr6+ penetrates the skin and enters the bloodstream. 7 If skin is mechanically damaged (cuts, abrasions), it is feasible that Cr6+ and other allergens can penetrate it .
Worksite skin cleaners too often are caustic and abrasive. They may contain sensitizers like lanolin, limonene, or perfume and they may contain irritants like alcohol.
can determine whether a worksite material will cause skin problems.
Environmental factors can cause skin problems directly or they can work with other factors to increase skin problems:
Heat causes sweating. Sweat can dissolve chemicals on the skin. Heat increases blood flow at the skin surface and this increases the absorption of materials into and through the skin.
the skin and causes microscopic cracks, sometimes known as winter
eczema. Cold changes blood flow at the skin surface and leads
to loss of feeling.
Humidity increases sweating. High relative humidity (RH) keeps sweat from evaporating. A 1998 study showed that epidermal homeostasis and barrier repair following acute insult are better supported in a low humidity (RH<10%) environment rather than in high humidity (RH>80%). 17 Recent data suggest 40-60% RH is optimal.
Sun burns and damages skin. Sun can increase absorption of chemicals. Some chemicals react with sunlight to cause photosensitization and photoirritation. Sun exposure alone can also cause skin cancer.
From 1983 to 1994, the rate of reported occupational skin diseases rose from 64 to 81 cases per 100,000 workers. In 1994, there were approximately 66,000 new reported cases of occupational skin diseases.
What Do Skin Problems
From 1983 to 1994, the rate of occupational skin diseases increased from 64 to 81 cases per 100,000 workers. In 1994, there were approximately 66,000 new reported cases of occupational skin diseases. Reported skin diseases are current ly about 10 to 15% of all work-related disease (BLS).
Moreover, occupational skin diseases are believed to be severely underreported. The true rate of new cases may be many fold higher than documented. No one knows how many family members are affected by contaminants brought home from the job.
Estimated total annual costs (including lost workdays and loss of productivity associated with occupational skin diseases) may reach $1 billion annually. Workers' compensation claims rates for occasional skin diseases vary by State and range from 12 to 108 per 100,000 workers per year. Self-reported occupational dermatitis prevalence in the 1988 National Health Interview Survey was nearly 2% (1,700 cases per 100,000 workers).
The costs to employers
include worker compensation disability claims, lower productivity, and
poor morale. The costs to the workers include reduced earnings, medical
bills, loss of a trade, social disability, embarrassment, and lower quality
The rates of most other occupational injuries and disease have fallen. But skin disease rates remain constant or actually increase. Little progress has been made, even though the causes are better understood and more methods of control exist now than ever before.
The NIOSH homepage (www.cdc.gov/niosh) presents additional information. Two reports explore the public health impact and epidemiology of contact dermatitis. 35,36
More than 92.7 million metric tons of portland cement were consumed in U.S. construction in one recent year, according to the Portland Cement Association.
The consumption of
Portland cement has increased every year since 1991.
More than 1.3 million American workers in 30 occupations are regularly exposed to wet Portland cement products. Thousands moresuch as ironworkersare exposed to cement dust during the grinding of hardened cement products.
Cement is a mixture of lime, silicates, aluminum, iron, magnesium, and other additives such as gypsum, fly ash, and blast furnace slag. Portland cement is a component in:
More than 1,300,000
American workers in 30 occupations are regularly exposed to wet cement.
Their families may be exposed to cement dust on their work clothes.1
Following is a partial list of the construction trades workers who may be regularly exposed to cement:
Below are some of the work tasks that expose construction workers to Portland cement:
The Nature of Cement
Cement has many properties which are damaging to skin. Cement is alkaline, or caustic. The pH of wet cement ranges from 12 to 13. Cement is hygroscopic, pulling moisture from the skin. Cement is abrasive. Cement may contain sensitizing chemicals and metals, such as hexavalent chromium (Cr6+)
The composition of cement varies somewhat from region to region. However, the alkaline, abrasive, and hygroscopic properties of cement in concrete, mortar, grout, plaster, stucco, and other products are universal.
Perhaps most frequently damaging of all these properties is the alkaline pH.
No matter what the cement product or work task, the most frequently damaging property of cement is its alkaline nature.
pH is a measure of
the acidity or alkalinity of a substance. The pH scale ranges from pH
0 on the acidic end to pH 14 on the alkaline end.
The acidic pH range is pH <1 t o 6.9. The alkaline (base) pH range is pH 7.1 t o 14. Strong acids are pH 1 to 3. Strong alkalies (bases) are pH 12 to 14.
pH stands for potential of hydrogen. It refers to the concentration and activity of hydrogen ions in a substance in aqueous solution (water). Acids ionize in water to give H + (hydrogen) ions. Alkalies (bases) produce OH - (hydroxyl group) ions in water.
An ion is an atom
that has lost or gained one or more electrons and has acquired an electric
charge. Cement contains calcium hydroxide which liberates hydroxylions.
The use of scientific notations to describe the hydrogen ion concentrations of substances is cumbersome. So chemists began using the pH scale in 1909.
pH-neutral is 7. This is the pH of pure or distilled water. It is virtually free of hydrogen ions.
The pH scale is like the Richter scale for earthquakes. Both are logarithmic. On a logarithmic scale, the intervals between the numbers are not equal. Every whole number on the pH scale represents a 10-fold change in alkalinity or acidity.
pH 13 is one million times more alkaline than pure water at pH 7. pH is one million times more acidic than pure water.
Wet cement is extremely alkaline, with a pH value of 12 t o 13. Strongly alkaline material is caustic and corrosive to skin, eyes, and mucous membranes.
Wet cement is 10 million to one billion times more alkaline than normal human skin.
A recent study found that barrier recovery proceeds normally when exposed skin is treated with solutions buffered to an acidic pH. In contrast, the initiation of barrier recovery is slowed when exposed skin is treated with neutral or alkaline pH solutions, regardless of buffer composition.15
The pH of Normal Skin
Normal skin is pH 4.5 to 5.5, meaning it is moderately acidic. The acidic pH of skin has been recognized for a century. However, the function of the acid mantle of skin remains incompletely understood. Scientists believe it has to do with provision of the proper milieu for the extracellular processing of certain lipids (fats) required for barrier function. 4,13
Like an orange, normal skin is mildly acidic.
Contact with wet cement changes skin pH from acidic to alkaline. At alkaline pH, barrier recovery is slowed, damage is prolonged, and skin problems are exacerbated.15 Alkalinity is essential in the development of irritant contact dermatitis (ICD) from cement. 3
Alkaline pH contributes greatly to skin absorption of the hexavalent chromium (Cr6+) in cement.18 So absorption of Cr6+ may be increased when it contacts skin in cement.
As a safety & health practitioner, you can measure the surface skin pH of cement products workers. Elevated pH is an indicator of portland cement residue on the skin.19 It demonstrates the effectiveness or ineffectiveness of protective measures. pH also serves as a feedback mechanism for education workers about the need to protect their skin from cement.
The best way to measure surface skin pH is with pH indicators, also known as pH color test strips. As an educational tool, pH test strips also can be used to measure the pH of cement residue on car seats, steering wheels, boots, glove interiors, and more.
Full range color test strips (pH 1 to 14) work best for cement contamination.
How To Use A pH
To test skin or dry surfaces, moisten a strip in distilled water. Apply it to the test surface. To test a liquid, dip the test strip in the liquid.
The strips come with a color coded scale. Hold the test strip next to the scale. Hold the test strip next to the scale and wait for it to change color. Then match it with the color on the scale to find the pH value.
pH represents the acidity or alkalinity of a watery solution on a scale. Pure water has a pH of 7. pH 7 is considered pH-neutral. Citrus and vinegar are pH 3.510 times more acidic than normal skin. Wet cement is 10 million to one billion times more alkaline than normal skin.
pH Testing Exercises
Supplies: dry Portland cement, household vinegar, one gallon distilled water, pH test strips, plastic glasses, plastic spoons, bar soap, liquid soap. Along with vinegar, you may consider testing one of the buffering or neutralizing products.
also can test the pH of exposed hands, gloves, hard hats, or the seats
and steering wheels in cars or trucks. Just dip a pH strip in distilled
water and lay it on the surface to be tested.
A pH test meter can be used to test tool rinse bucket pH. But cement particles in the water may clog this instrument.
pH Testing Conclusions
Cement product s workers probably will find the alkaline residue of wet portland cement on their skin and even on their clothes, their boots, their vehicle interiors, and elsewhere.
Removing t his alkaline cement residue requires clean running water and pH-neutral 20 or acidic soap. It may be protective to use a buffering solution in the workplace to normalize the pH of surface skin.21,22
Wearing gloves without
good hygiene appears to be no more productive than wearing no gloves at
all.3,19 and in fact may be worse.
More About Acids and Alkalies
Acids and alkalies (bases) react with one another so that the properties of both are lost to form water and a salt. The result is a more pH-neutral solution.
So adding an acid to an alkali tends to neutralize its pH. For example, adding vinegar to cement water can reduce the pH. But it also may generate heat.
Buffers are another choice for controlling surface skin pH. If added to an alkali, a buffer may reduce pH without generating heat.
Treating Skin with Solutions Buffered To An Acidic pH
Buffering solutions are equilibrium systems that maintain a constant pH when combined with acids or alkalies. A buffer can neutralize either an acid or an alkali. Buffering solutions typically contain similar amounts of a weak acid and a salt of its conjugate base.
Compared with acids, buffers generate less heat and can maintain the desired pH over a longer period of time. Phosphates are often used as buffering agents.
One important study of the role of pH in skin barrier repair following external insult concluded that "...maintenance of an acidic stratum corneum pH, either by preservation of the lipid barrier or by exoneously applied acidic buffers, is important to normal skin barrier function. [emphasis added]".15
Portland cement products workers may have difficulty in preventing 'insult' from wet cement. When cement residue accumulates on the skin, the application of a buffering solution may be beneficial in restoring the acidic pH of the stratum corneum, thus permitting the initiation of barrier repair and preventing skin problems.
A recent evaluation of buffering solution found that concrete truck drivers using a pH 5.5 buffering solution were more likely to see improvements in their skin problems than were drivers who used other treatment methods during a 30-day period.22
Commercial product s are marketed for acidifying t he skins stratum corneum. Neutralitetm is a pH 5.5 buffering solution. Mason's Hand Rinsetm is an acidic rinse. In theory, either product or similar products can be helpful if they normalize surface skin pH.
In addition to reducing the corrosive effect of cement, normalizing pH through the application of a buffering solution may convert hexavalent chromium (Cr6+) to trivalent (Cr3+). This would decrease skin absorption of Cr6+, reducing the risk of ACD.
This soap list is advisory only . To obtain reliable information, ask the soap's manufacturer for an MSDS. A pharmacist can recommend pH-neutral or moderaltey acidic soaps.
often ask whether cement can be modified to reduce the skin hazards. Different
modifications are proposed depending on the specific skin problem.
causes two main problems: irritant contact dermatitis (ICD) and allergic
contact dermatitis (ACD). Cement causes ICD because it is alkaline, hygroscopic,
and abrasive. Cement causes ACD because it contains sensitizers, not ably
hexavalent chromium (Cr6+).
have been several experiences with modifying cement to prevent allergic
contact dermatitis (ACD) from hexavalent chromium. Before reviewing results,
lets examine the cement manufacturing process.
Most cement manufacturing plants are located near quarries. Quarries mine the raw materials needed to make cement .
Huge quarried boulders of stone such as limestone and shale are dumped into an impact crusher. These raw ingredients, along with small amount s of iron ore and clay, may then be fed to a grinding mill where steel balls tumble to pulverize the material into a powder.
This powder may then be loaded into giant steel rotary kilns. The typical kiln may be about 200 feet long and 15 feet in diameter. The kiln interior is lined with refractory brick. As the kiln rotates, the inside temperature reaches 3,000 to 4,000 degrees Fahrenheit. The solid material must reach 2,600 degrees Fahrenheit.
The heat causes a chemical reaction in the raw materials as they slowly transform into portland cement. At this point in the process the cement compound is called clinker.
Clinker is dark gray chunks like volcanic rocks. The fully processed clinker falls out of the rotary kiln and down into t he clinker cooler where it cools it off for reprocessing.
The clinker is then ground in a giant rolling tube called a ball mill. Gypsum is added during t his grinding process.
The ball mill is filled with several tons of metal balls. Often, these balls are chrome or chromeplated. As the mill spins, the metal balls crush the clinker into an extremely fine dust and mix it with the gypsum until it becomes portland cement.
Samples of the finished product are taken to a lab for strength and consistency testing. The final product is shipped in bulk by truck and rail or packaged in bags. Cement is used in the manufacture of plaster, stucco, mortar, grout, and other cement products.
The major sources of chromium in cement are the kiln feed raw materials, refractory brick in the kiln, and wear metal from the media and liners and in the mills.5
The chromium content of Portland cement may range between 1 and 30 ppm but is usually less than 20 PPM The hexavalent chromium (Cr6+) content is usually less than 30% of t he total chromium. When clinker is ground wit h chrome alloy balls, t he Cr6+ content of the cement may increase to more than twice that present in the original clinker.5
The European Experience: Reductions in Chrome-Induced Dermatitis
Recognition of the connection between hexavalent chromium in portland cement and allergic contact dermatitis in cement products workers first emerged in Europe during t he 1950s. As the evidence mounted, some European countries acted to limit exposure to hexavalent chromium in cement products.
By law, Denmark and Sweden require cement manufactures to produce cement whose concentrations of Cr6+ are 2ppm or less. In these countries, a patented process is used which involves intergrinding of clinker, gypsum, and ferrous sulfate heptahydrate to reduce chemically the Cr6+ to trivalent chromium (Cr3+).
Cr3+ is not harmful to human skin because it is not absorbed by the skin.
A similar patent was granted to an East German company in 1985 and another to a Japanese firm in 1991. Additional patents were granted in other countries in subequent years.
Finnish, Danish, Swedish, and other scientists have published studies showing that this method of modifying portland cement at the plant has greatly reduced ACD in Portland cement products workers in Scandinavia and Singapore.18,23,24,25,26,38 ICD rates in these countries remain unchanged.
ACD from portland
cement is a common occupat ional dermatitis among construction workers
and a reduction in the chromate content of cement would be a reasonable
The American Experience:
In response to Californias Proposition 65 regulations, some American cement manufacturers experimented with iron sulfate in an effort to reduce Cr6+ in Portland cement .
In a published report of the results5 and in other forums, several reasons have been given for the failure to replicate the Scandinavian results.
"...[I]t would seem quite difficult to successfully intergrind ferrous sulfate heptahydrate with clinker and gypsum in any large finish mill due to the large circulating load of the mill/separator system, the elevated mill temperatures, and the high-volume air sweep. All of these factors would lead to the ready oxidation of ferrous iron."5
More than 120 plants make U.S. cement and t he product ships long distances in this country. If ferrous sulfate is added, the time it takes to transport the cement may result in spontaneous oxidation of the ferrous ion to the ferric form, rendering the ferrous sulfate inactive.
The addition of ferrous sulfate during grinding is a patented process. Royalties and the cost of the ferrous sulfate (variously estimated at $.05 to $1.00 perton) would increase the cost of American portland cement products. Added costs may be incurred in reconfiguring manufacturing processes to allow for the addition of ferrous sulfate.
As an alternative, some researchers have recommended that ferrous sulfate be added during mixing of concrete or when delivering premixed cement products to the worksite. 9,24
Finally cement products may be modified in another way to reduce Cr6+ levels. Slag can be substituted for clinker at the plant. 25
American manufacturers express concern about possible effects of such methods on the structural integrity of finished concrete. For example, some argue that addition of substantial amounts off errous sulfate to concrete might cause durability problems or necessitate adjustment of the amount of gypsum added.
Concrete in Europe and Singapore appears unaffected by modifications to cement in those countries. Manufacturers point out that American specifications for concrete are rigid, that any changes must be well researched, and that research is in fact ongoing. So change may be possible some day.
Neutralize pH at the Plant?
Some in the industry have asked manufacturers to reduce the alkalinity of cement.
By nature, wet port land cement is pH 12 to 14. Attempts to neutralize the pH of cement would chemically alter it . For example, the amount of buffering solution needed to neutralize a batch of cement at the plant would overwhelm the chemical formulation of the cement . It would no longer be cement.
Rather than attempt to neutralize the pH of an entire batch of cement at the plant, it seems more feasible to reduce the pH of the comparatively small amount of cement that may contact the surface skin of cement products workers at the jobsite. This can be done with a neutralizing or buffering solution.
As an additional benefit, neutralization of pH also may convert Cr6+ t o Cr3+, rendering the iron sulfate controversy irrelevant.
Neutralizing the pH of portland cement during the manufacturing process is not feasible.
Protecting skin is not simply a matter of wearing gloves. A substantial portion of cement products workers already wear gloves. To be effective, glove wear must go hand-in-hand with proper hygiene. Hygienic practices and use of the correct gloves will prevent contact with cement. Glove wear without good hygiene is no more protective than no gloves at all.3,19 In fact, it can make problems worse.
This chapter presents
the best protective practices for preventing skin problems from Portland
Not everyone can do all these practices. But every cement products worker should do as many as possible, beginning with the easiest ones. There is no guarantee that any or all of these practices will prevent skin problems from Portland cement . But these practices are recommended by experts and they represent the best protections known.
Practices at Home
pH-NEUTRAL OR ACIDIC SOAPS
Portland cement products workers should wash with pH-neutral or moderately acidic soaps.
Alkaline soaps may be fine for the general population. But cement products workers who wash with alkaline soaps continue to 'insult' their skin with alkalies. Remember, alkaline pH impedes barrier repair.15
If cement products workers wash with pH-neutral or acidic soaps, it may help restore the desired pH balance of the surface skin.
WASH WORK CLOTHES
Warn cement workers to launder work clothes separately to protect family or roommates. Run washer empty after work clothes load.
Remember Ted Jason's daughter?
are motivated to take protective measures when they believe they are protecting
So convincing portland cement products workers to launder work clothes
separately may be a good first step to adopting more best practices.
Practices at Work
Consider providing buffering spray to reduce the pH of contaminated surface skin.
with abrasive or solvent-containing products. These include waterless
handcleaners like alcohol-based gels or or citrus cleaners based on limonene.
Such cleaners are not suitable for cement exposure.
PROMOTE HAND WASHING
BEFORE PUTTING ON GLOVES AND AGAIN IF GLOVES ARE REMOVED
Gloves on dirty hands trap contaminants against the skin. Workers should wash with pH-neutral or slightly acidic soap and clean running water, as noted in the Portland Cement Association's sample MSDS. If workers remove gloves during work, they must wash again. If not, cement will enter gloves. Workers should not rinse their hands in tool rinse buckets.
A worker should dry hands with a clean cloth or paper towel before putting on gloves.
CEMENT ON SKIN OR CLOTHES
When wet cement gets on permeable clothing, remove it immediately. When wet cement gets on skin, wash with clean water and pH-neutral or acidic soap. At the least, consider using a buffering spray to reduce alkalinity.
ENCOURAGE LONG SLEEVES TAPED INSIDE GLOVES
Many experts recommend wearing long sleeve shirts taped inside gloves.
DISCOURAGE JEWELRY AT WORK
Cement can collect under rings, watches, or necklaces. Wet cement trapped against skin for long periods of time is hazardous.
TO CHANGE WORK CLOTHES AT WORK
Removing work clothes at work cuts exposure for workers and their family members. It keeps cement out of the car or truck interior.
If work clothes cannot
be left at the job, they should be taken home in a separate container.
A trash bag works great.
DISCOURAGE USE OF LANOLIN, PETROLEUM JELLY, AND OTHER SKIN SOFTENING PRODUCTS AT WORK
Skin-softening substances can seal or occlude portland cement residue to skin, can increase the skin's ability to absorb contaminants, and can irritate and sensitize the skin.
Never use petroleum jelly or other emollients to treat cement burns. Applying such products can intensify burns by trapping the cement residue against the skin.
Skin-softening products should be applied only to clean skin in clean environments. A cement products worker may use these products, if desired, at home after showering or bathing with pH-neutral or slightly acidic soap. A recent study found one common product effective in skin barrier enhancement.28
Some skin-softening products may contain fragrances, lanolin, or other chemicals that can cause ACD in susceptible workers.
DISCOURAGE BARRIER CREAM USE
Barrier creams or 'invisible gloves' are not recommended for Portland cement work. 29,39 The abrasive cement probably breaks the seal of the barrier cream. Also, reapplying the cream in the work area may occlude the seal cement to the skin.
ENCOURAGE GLOVE LINER USE
Glove liners of thin cotton help make gloves more comfortable. They can help keep hands clean and dry. But they must not be contaminated with cement inside the gloves. The goal is to keep the insides of the gloves clean.
Clean reusable gloves daily. Follow t he manufacturers instructions. Place clean gloves in a baggie. Store gloves away from tools and materials in a dark, dry place where the temperature is not too high.
THROW OUT GROSSLY
Sometimes gloves get so contaminated they cannot be cleaned. Throw them out.
PROMOTE DISPOSABLE GLOVES
Disposable gloves can make it easier to keep hands clean. Disposable gloves can be less expensive than reusable gloves. The only drawback to disposable gloves is that workers sometimes wear them too long. To remove disposable gloves, peel back from the top, turning them inside out. Discard disposable gloves at the jobsite each day.
Disposable gloves can make it easier for workers to keep their hands clean. Disposable gloves can be less expensive than reusable gloves. The draw back to disposable gloves is that workers often wear them too long.
How To Choose
The main goals for
successful glove wear are:
Some gloves combine rubber or butyl with cotton, other fabrics, or leather. Glove thickness and the length of the cuffs vary by task or worker preference. All-fabric or leather gloves are not recommended because they may become saturated with wet cement.
Gloves on workers are no proof of protection. Don't fool yourself: Without good hygiene, gloves are no better than no protection at all.3,19 If workers can't wash with clean running water and pH-neutral or acidic soap whenever they remove their gloves, the insides too easily become contaminated.
to consider when selecting gloves include: Workers should be
allowed to choose among equally protective gloves, whenever possible. Below are the
websites of two well-known glove manufacturers. Gloves can be purchased
from these and others or through a local safety supply store listed in
the business section of the telephone directory.
Workers should be allowed to choose among equally protective gloves, whenever possible.
Below are the websites of two well-known glove manufacturers. Gloves can be purchased from these and others or through a local safety supply store listed in the business section of the telephone directory.
SHOW WORKERS HOW
TO REMOVE REUSABLE GLOVES
When workers wear the correct gloves, they still must avoid contamination when they remove the gloves. As a safety & health practitioner, you can demonstrate proper met hods for cleaning, removing, and storing gloves. Before removing gloves, clean the outsides by rinsing or wiping off wet cement. Follow manufacturer's instructions. Watch for pinholes which can let in contaminated rinse water.
To remove gloves,
loosen them on both hands. Hold hands down so contaminated water will
not drip onto skin or clothing.
Remove the first glove only to the fingers. The cuff of the glove will remain over the palm.
Now, grabbing the
second glove with the first glove, remove the second glove. The first
glove should slip off.
Try to handle gloves
by the insides only. Don't touch the outsides.
URGE WORKERS TO
SEE A PHYSICIAN FOR SKIN PROBLEMS
Any worker with a
persistent skin problem, even a minor one, should see a physician. A statistically
valid survey of apprentice cement masons showed only 7% of those with
skin problems saw physicians even though 71% had had problems in the last
year.6 Some did not think the problems were serious. Others were afraid
of losing employment.
To get effective treatment , the cement products worker must inform the physician about products used at work. The goal is to provide medical treatment for a health problem.
A Physician Alert brochure is available from CPWR – Center for Construction Research and Training (301-578-8500 or www.cpwr.com) . The brochure can be given by a worker to a doctor, along with the product Material Safety Data Sheet.
to follow the physician's prescriptions and recommendations. That action,
combined with other best practices, can lead to the successful control
of most cement-related skin problems.
THE MODEL MSDS
Find the best Material
Safety Data Sheet in the industry and review its recommendations.
The best MSDS is
the one that is most complete and provides the most protective recommendations.
Remember, this MSDS is only the minimum guideline. With a little creative thought and not too much effort, employers and workers can do a lot more to prevent skin problems.
Best Practices in Emergencies
Dusty clothing or clothing wet with Portland cement fluids should be removed promptly and laundered separately before reuse.
Workers must wash wet cement from the skin with clean water and pH-neutral or acidic soap. Workers cannot rely on pain or discomfort to alert them to skin damage.
An acid will burn skin immediately. Cement is sneakier. A worker can work with wet cement on the skin for hours without feeling any discomfort . But the alkaline burns of the port land cement are damaging the skin microscopically. That damage may be just a cement burn or it also may be the cumulative injury that leads to irritant or allergic dermatitis.
Cement burns are alkaline burns (caustic burns). Cement burns progress. This means they get worse even without more exposure. Anyone who feels a cement burn starting should go immediately for emergency treatment in an ER or by a burn specialist. Don't assume the burn will not get worse. By the time an employee becomes aware of the burn, much damage has already been done and further damage is difficult to stop.
Medical experts recommend flushing the skin with lots of clean water. Some suggest adding vinegar, citrus, or a buffer to the water to neutralize the caustic effect . 15,21,31,32,33,37
When cement burns are treated medically, recovery takes place within two to three weeks. If untreated, these burns take much longer to heal, if they ever do.
Almost everyone agrees the construction industry must do more to protect workers from skin problems. As a safety & health practitioner, what resources can you use to improve protection for cement products workers?
The PRINTER-READY PULL OUTS in this guide can help: Worker Safety Pamphlet, Best Practices Checklist, and Symptoms Questionnaire. This chapter also presents some additional tools and pointers to help you achieve your goals.
Save Your Skin Booklet
Save Your Skin, an 8-page booklet explaining proper glove wear f or work with wet Portland cement products. (Remember, 'wet cement' can include cement dust on moist skin.)
CPWR – Center for Construction Research and Training
Sample Material Safety Data Sheet
The Portland Cement Association offers a sample Material Safety Data Sheet. 20 Recommendations include washing on the job with running water and pH-neutral soap.
Portland Cement Association
Training Video for Concrete Work
Skin Safety with Cement and Concrete, a worker training video, is for sale from the Portland Cement Association. The video presents safety tips and hazard information. It focuses on cement burns rather than on preventing dermatitis.
Cement Burn Kit
The Cement Burn Awareness Kit is available for purchase from the National Ready Mixed Concrete Association for use in educating Portland cement products workers.
The kit contains color photographs of severe cement burns, warning tools, and a sample MSDS to help prevent cement exposure.
Mixed Concrete Association
Save Your Skin Tool Box Pamphlet
Save Your Skin: 15-Minute Tool Box Session is an 8-page booklet explaining symptoms, skin problems, pH testing, and protective practices for work with cement products.
CPWR – Center for Construction Research and Training
pH Color Test
Buffers And Neutralizers
Commercial products are now marketed for buffering or neutralizing the pH of cement residue. NeutraliteTM; is a buffering solution. Masons Hand Rinseä is an acidic rinse. Each is spray-applied. In theory, these or similar products can be useful if they neutralize or buffer alkaline residue on the skin surface.
Mason's Hand Rinse
Let's say you want to invest time and effort in improving conditions with the aim of preventing skin problems from portland cement.
How will you know if your efforts pay off?
You might say, It's easyI'll see the improvement with my own eyes. It will be plain to everyone. But that may not be true.
Whether your responsibilities as safety & health practitioner involve five cement products workers or 500, you can set up a system for measuring t he success of your prevention efforts. This chapter gives some simple ideas about how to do it
There are two very good reasons to evaluate your prevention efforts. One is to get the feedback you need to improve your efforts. The other is to justify their continuation.
Compared To What ?
When you evaluate anything, you need a basis for comparison. Two classic methods of evaluation are criteria-based' and norm-based' comparison.
Criteria-based means comparing something with an objective standard that's set up ahead of time. For example, if a teacher grades tests by an objective standard and gives an A' only for 100%, that's criteria-based' evaluation.
Norm-based means comparing something with other things in the same category. For example, if a teacher "grades on a curve" by comparing a student with other students in the class, that's 'norm-based' evaluation.
To measure your success in reducing skin problems from cement, first choose your own basis for comparison. Do you want to compare your results with an objective standard of 100% healthy skin and perfect protective practices? Or should you measure progress by comparing results with existing conditions?
Always remember that you are not evaluating the workers. You are evaluating the effectiveness of your own efforts to change their protective practices and to improve the protections provided by the employer.
standard you choose, here are three tools you can use to measure your
results. You might also think of other tools.
Consider comparing the workers, as a group, with themselves before and after beginning your prevention efforts.
Before you begin, take some baseline measurements. You can use the Best Practices Checklist and the Symptoms Questionnaire in this guide. For example, watch workers on the job and take reports of what they do at work and at home. You are not comparing individuals. You are comparing the workers as a group before and after your efforts.
Which best practices are the workers currently doing? Which are they failing to do? Keep a written record of your observations. Have the workers complete the symptoms questionnaire. Assure them the information will not be released in personally identifiable form and that their answers will have no effect on their employment. Ask them to do a pH test of surface skin. Again, this is not a test of the individual worker. Instead it is a measure of the success of the protections implemented by you, the safety & health practitioner.
Once you have a baseline record, begin your effort to reduce skin problems. Teach workers best protective practices and make what improvements you can in working conditions.
When you think your efforts may be starting to pay off, repeat your measurements. If you made worksite observations, make them again. If you collected best practices checklists, collect them again. If you collected symptoms questionnaires, collect them again.
Now count the results and compare the BEFORE' and the AFTER.' If you or someone in your organization knows how to use a statistical software program, it can help your evaluation. Or you can count by hand calculator and determine where it appears there has been progress. Repeat the measurements again in a few weeks or a few months. Keep a long-term record of the outcomes.
Take the same measurements
periodically to assess progress. The results can help you adjust your
What If Workers Are Transient?
In construction, workers often come and go. Turnover varies from company to company. Some larger companies have a steady cadre of core workers and hire or layoff more as projects demand. Other companies have no steady workers, only transient ones. This makes evaluation more difficult. But not impossible.
Always keep in mind that you are not evaluating individual workers. You are evaluating the success of your efforts by looking at all the workers as a group.
If all the workers are transient, you may not see immediate improvements in the symptoms checklist. But you should see improvements in the pH tests of surface skin and in compliance with best protective practices. This should help prevent future dermatitis.
Work With Others
By working with other organizations, you can help to reduce skin problems among the cement products workers whose safety and health is your professional concern. If possible, involve the health & welfare plan and implement a plan-wide evaluation in medical costs and workers compensation disability.
Best Practices Checklist
SURFACE SKIN pH TESTING
This questionnaire is designed specifically for Portland cement products workers. Please fill it out by placing a check mark in the box that represents the best answer. Do not worry if you cannot answer every question exactly. Remember, if possible, collect the Material Safety Data Sheets (MSDS) for the materials you work with before visiting your doctor for any skin problem.
Do you keep your
skin clean and dry by wearing any of the following protective gear?
What other kinds of work do you do? ______________________
What hobbies do you do? _______________________________
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