Metals Safety Information
Goldsmiths work with metals. Our bodies react to metals, their dusts, salts and oxides. The metals that jewelers come in contact with include gold, copper, silver, zinc, iron, steel, platinum, palladium, rhodium, iridium, titanium, niobium, aluminum and ones that we should consider not having around any more at all in the workshop: nickel, lead, mercury, chromium, selenium, cadmium, arsenic, antimony, manganese and beryllium. Alloys contain more than one metal, brass for instance, contains up to 35% zinc, the rest is copper.
Besides touching them, the most common ways we contact and encounter metals are as compounds (often salts or oxides), in patinas, cleaning, pickling, enamels, by-products of heating or chemical reactions in the course of working in the jewelry shop. The addition of heat to metals, as when we solder, anneal or melt, accelerates chemical and physical reactions of all kinds, and causes some reactions that do not occur at room temperature (Stellman and Daum 275).
We need certain amounts of most metals in our bodies-but not too little or too much. Metals have “concentration windows”: that means that too little contact may be damaging, and too much may be really damaging. The exposure window can be very small in some cases-it is easy to have too much contact with some metals. Exposure to multiple metals can result in interactions between them, which causes greater damage than exposure to a single metal alone. An example is the interaction of cadmium and zinc, or the ability of lead to displace calcium in the body, and thus affect the nervous system (Waldron 13). I have heard several anecdotes of metal toxicity among jewelers (who ate, drank and smoked cigarettes in their studios). The metals mentioned included antimony, aluminum, palladium, gold and silver (thought to interfere with selenium absorption). The metals appear to have built up in their bodies over a long period of time. Our literature search didn’t turn up much information about such metal toxicity in jewelers and I would advise you to talk to your doctor about it for current information. Pre-existing medical conditions might in several of these cases have made the individuals more susceptible to metal absorption.
Self-dosing of metals in the form of supplements can be a concern; there have been several cases of chrome poisoning from this. Have a look at what you are consciously ingesting as well.
Again, you are exposed to metals by touching them, by breathing or ingesting their oxides, salts and dusts and, at higher temperatures, their fumes. Metal fume fever is a real hazard with molten metals. Zinc, copper, magnesium, aluminum, copper, antimony, cadmium, iron and silver can cause metal fume fever.
The following metals have been linked with liver damage: antimony, arsine, beryllium, bismuth, cadmium, manganese and selenium (Stellman and Daum 39) as well as indium which can hurt your kidneys too, irritate and permanently damage your lungs and probably affect your fetus if you are pregnant (NJDH).
Sometimes people react to jewelry they are wearing. Cosmetics use exacerbates the effects of a metal on the skin. A study was done with almost 1000 metal-intolerant patients. All were patch-tested with nickel sulfate and wore metal washers as a neckpiece. “63% reacted to nickel sulfate (patch test), 50% reacted to the nickel washer, 8% to the nickel-palladium washer, 13% to the copper washer, 7% to the brass washer, 4% to the bronze or palladium washers, 2% to gold and none to iron” (Veien 86). So it looks like iron might be the best material for jewelry in terms of metal tolerance. That should make the blacksmiths happy.
The worst metals to have around, as metals and in alloys and salts, include cadmium, nickel, chromium, antimony, arsenic, and beryllium
The body does not absorb aluminum easily and the skin, lungs and gut all act as effective barriers to absorption. Exposure to high levels of aluminum powders and dusts can cause a kind of lung disease. At this point there is no evidence that aluminum causes Alzheimer’s disease and North American specialists generally see European bans on aluminum cookware as premature (Waldron 40-41). While it is true that Alzheimer’s patients can show high levels of aluminum in their brains it is possible that if you have Alzheimer’s, you accumulate aluminum in the brain more than someone who doesn’t, rather than that aluminum causes Alzheimer’s.
Metal fume fever can be a hazard and chemical pneumonia can happen to people smelting aluminum (Tver and Anderson 2). Melting aluminum requires good ventilation.
One of my students is anemic and when working with aluminum for a project was diagnosed by her doctor and specialists as saturated with aluminum, to toxic levels. I had never heard of this, nor did others in the class suffer in the same way and the thought is that perhaps her anemia made her more susceptible.
Antimony is used in certain Japanese alloys, some solders, and in pewters. Industrial antimony is frequently contaminated with arsenic. Another metal to avoid, especially as fumes (Waldron 43). Antimony is associated with cardiovascular abnormalities and changed EKGs in bronze and pewter workers (Tver and Anderson 46).
You should not be using it. Some alloys from Japan (such as koromi-do) may contain arsenic. My recommendation-don’t use them, and if you feel you need to, then don’t melt them or get them too hot. Arsenic has been shown to be a carcinogen, and multiple skin tumors have been associated with ingestion and inhalation (Emmett 165). Arsenic exposure in alloy makers has been linked to increased death rates from heart disease (Tver and Anderson 46).
This is used as an alloy with copper. The addition of 2-3% beryllium makes a copper alloy which is “hard, corrosion resistant…and has greater tensile strength” (Waldron 270). Beryllium and beryllium nickel alloy are used be some jewelers as an addition to gold alloy castings to increase strength and hardness, even improving scratch resistance. This should not be done without excellent local ventilation, a good understanding of the materials and laboratory grade precautions. The ventilation exhaust position must be carefully considered. Using unknown copper alloys from the scrap yard, and heating them or alloying them is a considerable hazard. Eating beryllium is not too bad, but breathing its fumes or dusts is very dangerous, in immediate effects and as a significant carcinogen (Waldron 27-30). It causes acute and chronic lung disease as well as lung ulcerations (Waller 47).
Another one to totally avoid. Because cadmium was used in many solders and even alloys to improve fluid characteristics, you should watch out for old (cheap, inherited etc.) solders and even unknown metals. Send them in to the refiner. Cadmium in solder can cause pulmonary edema (“fluid in the lungs”, where your own fluid drowns your lungs from the inside out) [McCann, Health Hazards 57]. “Cadmium oxide fumes are a known human carcinogen” (AB! 457) Cadmium fumes and dusts are “extremely toxic, causing both acute and chronic lung disease and kidney disease” (Waller 47). Long-term exposure to low doses causes emphysema, kidney and liver disease, anemia, bone deterioration and can lead to prostate and other cancers in some people (Wedeen 455; Kinnersly 164, McCann HH 57)). There is also evidence that people who use cadmium solders lose the ability to smell certain chemicals (Shusterman and Sheedy 531). An acute exposure can kill you quickly. A welder who cut through cadmium-plated bolts on the Severn Bridge died rapidly (Kinnersly 165). Cadmium exposure in jewelry workers is also linked with high blood pressure, increased heart disease and death from heart disease (Tver and Anderson 46). Rossol says “All cadmium compounds should be considered highly toxic. Has adverse reproductive effects” (138).
It is a strong carcinogen and the rule with such things is: no exposure level is safe. Got that? No level of exposure to carcinogens is considered truly safe. So, no cadmium-containing materials should be allowed in your shop. Ask for MSDS sheets on your material and consider trashing the great deal on solder sheet or wire you got from an old lapidary club member some years ago (Waldron 23-26). Cadmium accumulates in the body, and with a half-life of 30 years can build up quickly to acute toxic levels if you are repeatedly exposed to it. About one third of the stored cadmium remains in the kidneys (Wedeen 256).
Bad stuff all around. Chromium may be contained in plating solutions, unknown metals (even some dental golds) and stainless steels. Don’t breath its fumes. Avoid contact with it or its salts (chromium plating for instance) (Waldron 31-32). People who cast with chromium-containing alloys risk occupational asthma among other things (Tver and Anderson 17). Chromium workers making chromate compounds have rates of lung cancer death as high as 22% and are 30 times more likely to get lung cancer than the general population (Tver and Anderson 258).
Jewelers, particularly craft and art jewelers, frequently use copper. It is alloyed with zinc to make brasses of different kinds. Bronze is also made with copper. Nickel is added to make nickel silver. Mass-produced fashion jewelry often contains copper or copper alloys. While copper can cause allergies, this is rare. Its salts, however (such as those found in patination and plating solutions), can be fatal if ingested and cause dermatitis if you have regular skin contact with them. Copper fumes can cause metal fume fever. Copper oxides, which are flung off the metal when it is worked, can be breathed in and increase the chance of problems with the material. It can be a good idea to pickle and rinse copper to reduce your copper oxide exposure. Copper plating solutions are either acid-based (often sulfuric) or dissolved with cyanide salts -which can be lethal if mixed with an acid.
Jewelers use gold both pure and in mixtures with copper, silver, nickel, zinc and other metals. It is very unlikely to cause dermatitis, though the metals it is alloyed with may. The lower the karat the more probable a skin reaction would be. Only 8-karat and other low-carat golds are likely to react with the skin at all. Fumes can cause metal fume fever. Gold plating solutions containing cyanide pose the same health risk as other cyanide-based ones. Gold exposure has been implicated in several kinds of kidney disease, though in what quantities and what form I was unable to track down (Tver and Anderson 171, 208-209).
Lead is bad. Don’t touch it much (use latex or vinyl gloves); don’t heat it or breathe the fumes. If you have a lead block around, keep it in a latex glove or other covering. Dusts and fumes are the primary hazards with the material (Waldron 13), but it can also be ingested and absorbed through the skin (hence the glove suggestion). Lead causes numerous problems in people and is a serious hazard. Avoid lead in your workplace (Waldron 13-18). Avoid leaded enamels, rubber molding compounds and paints.
Mercury is really, really bad. In lots of ways: short term, long term, chronic, acute (right away) and so on. Lots of citations, studies and hard-boiled evidence show what it does to people. Remember the mad hatter in Alice in Wonderland? Hatters went mad from exposure to mercury used in the felting process. And that was just for a start. Jewelers use mercury in gilding and silvering amalgams. It affects the central nervous system, kidneys, and “has adverse reproductive effects” (Rossol 143). Tests on animals show that mercury reduces male sex drive, causes infertility in males and females, causes miscarriages, birth defects, retards the growth of babies, and contaminates breast milk (Rossol, “Pregnancy” 22). There is currently debate about mercury fillings releasing mercury into your body and many dentists are replacing mercury with other materials, though it has been pointed out that grinding the amalgam out to change it releases lots more mercury than any hypothetical leaching would (Dr. Dule, Orchid list, 6/13/99, Re: (Orchid) Gold teeth).
Basically don’t mess with it at all as a jeweler. If you have to use mercury, use it only in a university-level chemical lab with lots of understanding of its effects.
Ramazzini talks of the dangers of mercury poisoning a great deal, with goldsmiths and gilders being prime sufferers of the effects: “Craftsmen of this sort very soon become subject to vertigo, asthma and paralysis. Very few of them reach old age, and even if they do not die young their health is so terribly undermined that they pray for death. Palsy of the neck and hands, loss of teeth, uncertain gait…” (34). He goes on to describe numerous case studies of the effects of mercury. The details of their deaths are so repulsive that it really puts one off any desire to work with the stuff. And while I have in the past, I would not do so now without stringent precautions and the right equipment.
Miners of all metals in Ramazzini’s time were usually condemned prisoners and life was short. One of the worst mines to be sentenced to was a mercury mine. One man, sentenced for six months became “so impregnated with mercury that if he held a bit of copper to his lips or handled it, it turned white” (Ramazzini 22).
Mercury was once used as a cure for syphilis. It was rubbed daily into the skin of the syphilitic patient. Eventually their toxicity built up so high that the syphilis germs were killed and they were “cured.” Of course, they had to live with the effects of mercury poisoning…
“Early symptoms of [mercury] absorption are psychic and emotional disturbances. Symptoms can progress to tremors, kidney disease, and nerve degeneration” (Rossol 143). McCann gives the following symptoms for acute mercury poisoning: “a metallic taste, excessive salivation, swelling of the gums and mouth, vomiting, bloody diarrhea, possible kidney failure, and, in case of inhalation, possible bronchitis and pneumonia” (McCann, AB! 444). Chronic poisoning, where the mercury builds up in your system over time, eventually produces the same symptoms, but also affects your central nervous system, which in turn leads to “muscular tremors, irritability, and psychological changes (depression, loss of memory, frequent anger, and indecision)” (McCann, AB! 444).
Jewelers use nickel because of its powerful “bleaching” effect when alloyed with other metals; as little as 5% nickel in a copper alloy can make it a white metal. Other examples include nickel white gold and nickel silver.
Nickel fumes are a proven carcinogen, and one of the principles of dealing with carcinogens is that no amount of exposure is safe (Tver and Anderson 258). Studies in different countries show an excess risk of nasal sinus, lung and larynx cancer in nickel refinery workers, though this risk is not noted as being higher for metal workers working outside refineries (Waldron 34). When proper ventilation and masks were issued to the nickel refinery workers, those who had been employed after the changes showed no more tendency to get cancer than the general population (Frank 78).
In 1999 in North America, it is still normal for jewelers to alloy their own nickel white gold with a commercially supplied pre-alloy containing nickel. This practice is, in my opinion, unsafe, and at some point will be unacceptable. Occupations involving nickel fume exposure include electroplater, enameler, jeweler and metalworker (Veien 88).
As well as being a carcinogen in the form of fumes from the melt (and reticulation if working with nickel silver), nickel is proven to be one of “the most potent” of skin sensitizers: that is, contact with the metal (as in jewelry) or its salts can cause various kinds of dermatitis and make one more susceptible to developing allergies to other metals. Waldron writes, “All those who handle nickel or its salts are liable to be at risk” (34). Dermatologists identify nickel as the most frequently occurring contact allergen-most people with contact dermatitis are reacting to nickel (Veien 81). Its dusts and filings are hazardous. Nickel salts are commonly used in electroplating. Nickel carbonyl has been used in the past for molds. It causes acute respiratory problems and cancer of the lung and nose (Waller 47).
Increasing allergies to nickel and other metals have been noted in Europe and North America in recent years-even to silver and gold. As a result, Europe and Japan are banning most nickel alloys (including nickel white gold), which will affect the ability of US manufacturers to export their jewelry. The reason that refiners in North America make nickel white gold is to make more profit; it costs less than palladium white gold to manufacture. This will no doubt change as North American manufacturers find their products barred from the European and Japanese markets. An interesting note is that many coins are made from nickel silver (an alloy usually made of copper and nickel). People therefore may have a fair bit of skin contact with nickel, and cases of contact dermatitis among people handling coins have been noted. About 10% of adult women show signs of nickel allergy (Veien 89). Many nickel-sensitive women work in cleaning jobs or are hairdressers. Exposure to cleaning compounds and wet work seems to be a factor in developing nickel allergies (Veien 91).
Nickel is found in much stainless steel, and this is used in fashion earring posts. Pierced ears have been identified as a major cause of nickel sensitization (Veien 84). Dentists recommend not having children’s ears pierced until all orthodontic work has been finished, to help avoid nickel allergies later in life (some new orthodontic procedures use titanium, both for strength and to avoid contact with stainless steel that contains nickel). Other concerns include body-piercing jewelry as a cause of nickel allergy. Sweat and household detergents can release nickel from stainless steel in quantities sufficient to cause dermatitis (Veien 85).
Some body piercers use kitchen-grade stainless steel, which contains a great deal of nickel. This is unacceptable. Only surgical steel should be used and even that has been linked to metal allergies. Even tiny traces of nickel (from the manufacturing process) found on niobium wires used for body piercing have caused importation problems into Europe under new regulations.
Nickel allergy lasts pretty much forever; in one study all 100 nickel-sensitive patients were still sensitive when tested 10 years after the initial positive patch tests (Veien 84).
Another, and perhaps more troubling, source of contact (and possibly a contributor to the increasing allergies to nickel and other metals noted in the population) is the use of finely divided nickel as a catalyst in hydrogenating oils (Waldron 33). Anyone eating processed foods (most processed foods contain hydrogenated oils-check your labels) is then apparently exposed to nickel through this route. However, having spoken with the head of a company which makes hydrogenated oils, it appears that there is no detectable nickel in the oil that particular company produces-that is, not above 0.5 parts per million. According to the nickel MSDS, children may drink a maximum of 0.04 milligrams of nickel a day in water. This is far above any hypothetical amount left in the oil by the company I spoke with, but there is still some concern in my mind in this regard.
Platinum and Platinum Group Metals
Platinum is being used more frequently be jewelers at the end of the twentieth century, partly in response to a very successful marketing campaign by the platinum producers group. Platinum is considered by jewelers in general a fairly benign metal in terms of toxicity. There are reports that platinum can cause a contact dermatitis in some people (Waldron 42). Platinum salts (not the metal), as are used in plating can cause dermatitis and rarely platinum poisoning (platinosis) if inhaled or in skin contact (Tver and Anderson 236). As always, lots of exposure is a bigger risk-platinum refiners can get occupational asthma (Tver and Anderson 17). Other metals in this group include rhodium, iridium and palladium, all of which are more or less similar to platinum. Fumes from them should be avoided. Their salts and plating solutions are dermatitis and chemical hazards and care is needed when working with them. Obtain the MSDS sheets for each metal in the group you use.
Scrap and Found Metals
Jewelers, goldsmiths and artists sometimes use scrap metals. Some metals may have platings containing mercury compounds, cadmium or zinc that, when heated, are a real health hazard. Be careful using scrap and found metals. I remember a surplus store I used to shop at frequently in upstate New York. It was filled with machines, surplus military electronics and intriguing bits of metals and tools. One day the newspaper reported a case of radiation poisoning in an employee at the place, and some of the surplus materials were “hot.” We went in there rather more cautiously for a while after that.
Jewelers most frequently encounter selenium in the form of Brass Black? and gun-bluing compounds. Selenium print toner (used by photographers) is sometimes used by jewelers as a metal coloring solution. These coloring mixtures usually contain selenic acid. Selenic acid can release hydrogen selenide gas which can cause illness, and if one used it daily, it might enlarge the liver and spleen (Tver and Anderson 157). Tellurium is sometimes used in association with selenium. Selenium dioxide is a by-product of copper and nickel melting, or of heating alloys containing selenium. The dusts are very irritating to the mucous membranes and the lungs. Contact can cause dermatitis (Waldron 42-43). Be careful about skin contact with selenium compounds. Selenium is considered very damaging to the liver (Tver and Anderson 180).
Silver does not appear to harm the body except by causing blackening (tattooing) of tissues where it is fixed. Silver dust may cause blackened spots in the eyes and on skin (it may even turn the testicles black). In cases of great exposure to silver dust and particles, silver granules have been found in internal organs upon autopsy, but no interference with function or health has been noted beyond this (Waldron 43). McCann writes: “Silver particles that become embedded in the skin can cause a permanent tattoo; in the eyes they cause a permanent blue-black stain. Chronic inhalation of silver dust of fumes can cause argyria, a permanent, bluish-black discoloration of eyes, nails, inner nose, mouth, throat, skin, and internal organs, which is very disfiguring but does not have any known ill effects. It may also cause clouding of the cornea, and decreased night vision might occur” (AB! 457) daytime vision too can be distorted by the discolored cornea, though this is a rare condition (Tver and Anderson 107). All forms of silver are cumulative in the body tissues and only a small amount is ever excreted. Silver clay, a colloidal material that when fired shrinks 10 to 40% contains mysterious supposedly non-toxic binders that ‘are found in the average Japanese kitchen. They are available in a number of silver and gold alloys as well as platinum. At this point there seem to be few worries about the material.
Silver does possess certain bactericidal characteristics. It is used to plate the insides of milk collection vats (it keeps bacteria growth down) and Alexander the Great, while traveling with his army, would only drink water from his silver helmet which had been sitting overnight-there are some suggestions that this may help purify water.
Silver is often dissolved with cyanides in plating solutions-which presents cyanide hazards. Silver is alloyed with gold, copper, zinc and other metals. Older silver solder alloys contained cadmium as well. For this reason, don’t use old solder without excellent ventilation. Goldsmiths used to use silver amalgams with mercury for silvering objects – this is now an unacceptable procedure.
Titanium and the Reactive Metals
Titanium is used in body implants and in orthodontic work, replacing stainless steel as a “safer,” less allergenic material. Which seems to imply it is pretty well inert as far as body contact goes.
Bill Seeley of Reactive Metals says that titanium dusts produced by filing and sanding are dangerous in the same way that talc is, basically as particulate matter and dust that can be inhaled. He knows of no other toxicity problem (Bill Seeley, personal communication, 12/18/96). I would suggest using local ventilation or an appropriate dust mask. Even better, work wet in some manner to keep the dust down, and damp-mop dusts.
Titanium powder can burn like magnesium if given enough oxygen. It is hard to do this but I mention it. I did hear a story about someone who had a meltdown on their miniature lathe when the thin shavings being produced ignited. An engineer who was a student of mine, Hale Sweeny, wrote to say that he had actually managed to set his titanium afire when trying to ball up a wire in the same way that one does with a silver one. He writes: “Imagine my surprise when the wire started burning just like a magnesium fire!!! Quickly dunked it in a pot of water, and gave up the idea of having balled-end pistels in my titanium flower! So you CAN make it catch on fire, if you work at it!” (Hale Sweeny, personal communication, 12/20/96). Power sanding and grinding operations are a potential place for this to occur as well.
Jewelers most commonly experience zinc as an alloy material in brasses (5-40%) and solders. Zinc chloride is used in some soldering fluxes. Zinc is alloyed with copper, silver and gold, among other metals. Spin casting for production fashion jewelry often uses zinc alloys. The chief hazard is breathing zinc oxide fumes when metals containing zinc are heated. Metal fume fever can result and these fumes can even be fatal if the exposure is very high (Waldron 32).
Goldsmiths and jewelers use all kinds of other materials in their work. These include gems, minerals, glasses, ceramics, innumerable plastics, polymer clays, organic materials such as woods, bones, shells, pearls, synthetic and natural resins, and just about anything at all when it comes down to it. Each material will have certain dangers and it is up to you to determine what problems your specific usage will cause you. Organic materials carry biological dangers (Anthrax with bones and wool, glucose replacement in the blood and lung damage with abalone etc.), dermatitis and allergy problems as well as particulate hazards, cotton dust for instance is very damaging to breathe. People working with plastics (which includes polymer clays) are exposed to an enormous range of chemicals, well over 120 in some cases (Kinnersly 408-10). Get your MSDS sheets together in the “Right to Know” binder and take great precautions against dust, skin contact and chemical exposure with such materials. Do not use materials in ways not suggested by the manufacturer, heating most plastics for instance evolves very dangerous fumes.