CHEMICALS & DUSTS

• Also known as RCF, Synthetic Vitreous Fibers, Fiber Blanket.
• Always read the SDS for any fire-resistant material and check for RCF.
• Some studies in animals have indicated carcinogen-potential. Other studies refute the findings. 
• Long-term exposure to respirable fibers may lead to lung scarring (fibrosis).
• When ceramic fibers are used at high temperatures (above ~1800°F), they may convert to crystalline silica (e.g., cristobalite), which is very toxic.

Toxicology:

• The International Agency for Research on Cancer (IARC) classifies RCF as Group 2b (possible human carcinogen).
• The  Seventh Annual Report on Carcinogens (1994), prepared by the National Toxicology Program (NTP), classified respirable RCF and glasswool as substances reasonably anticipated to be carcinogens.
• The American Conference of Governmental Industrial Hygienists (ACGIH) has classified RCF as “A2-Suspected Human Carcinogen.”

TLV: 0.2 fibers/cubic centimeter (8 hour TWA) – This is very low and indicates high toxicity.

Protection:

• Wear a P95 or P100 respirator when working with RCF.
• Avoid making the fibers airborne.
• Always vacuum RCF – never sweep.
• Buy a HEPA (High Efficient Particulate Air) filter for your shop vacuum.
• When changing the bag, seal the opening with tape to prevent fiber release.
• Dampen RCF with water to reduce fiber release.

• Chronic effects are Silicosis, Lung Cancer, Lung Fibrosis.
• ​National Toxicology Program (NTP) carcinogen classification: Known to be a human carcinogen.
• OEL/TLV: 0.025 mg/m3 (8 hour TWA).
• Also known as: Cristobalite, Quartz, Tridymite, Tripoli.
• You should avoid exposure!
• Always wear a P100 respirator when working with anything that contains silica!
• Found in kiln brick, silica flour used to make molds, some sand blast grits.
• NEVER use sand for sand blasting! Use only Silicon Carbide or Aluminum Oxide for sand blasting which has a Nuisance Dust classification.
• Historically found in whitening (used to be ground marble contaminated with silica).
• Never cut kiln brick dry with a power saw! Keep wet when cutting..

Always read the SDS for any material used. Sometimes silica is a component of other products.

• Nuisance Dust is not recognized to be the cause of any serious pathological conditions other than possible irritation.
• Examples: Ground glass, sandblast grits such as silicon carbide and aluminum oxide.
• However, very high exposures to nuisance dusts can cause disease. For example,  extremely high exposures to baking flour has been known to cause “Flour Mill Lung.”
• TLV: 10 mg/m3.

• OSHA classifies glass dust as a Nuisance Dust.
• Ground glass DOES NOT CAUSE SILICOSIS.
• N95 respirator is recommended to limit exposure.
• Glass is made from sand, which contains silica – a naturally occurring mineral silicon dioxide (SiO2).
• Crystalline forms of silica, also known as “free” silica, can contribute to the development of silicosis under prolonged exposure conditions.
• It is important to understand the difference between glass and crystalline silica because exposure outcomes are extremely different!
• Glass is a SILICATE containing various other ingredients which have been melted and upon cooling form an amorphous, or non-crystalline structure.
• While silica (SiO2) is a primary ingredient in the manufacturing of glass, when glass is formed under heat, the crystalline structure is changed to an amorphous structure and is no longer considered crystalline.
• Ground glass or frit is rarely respirable because the particles are too large.
• Always use wet methods when grinding glass. Water captures the dust.
• Sometimes other chemicals are used to add color to glass such as arsenic, lead, cadmium. These are usually present in low concentrations and are bound to the glass and not readily available but could present an exposure issue under some circumstances.

Bullseye Frit:

• Powder (0.2 mm and finer)
• Fine (0.2 – 1.2 mm)
• Medium (1.2 – 2.7 mm)
• Course (2.7 – 5.2 mm)

Only powder is possibly respirable. Fine is considered “inhalable” but is too large to be of real pulmonary consideration. 

Acidic foods such as orange or grapefruit juice, tomato juice, coffee, tea, tomato-based foods such as spaghetti sauce, wines and vinegar-containing foods cause more chemicals in glass to leach into the food than do non-acidic foods such as water or milk.  More chemicals in the glass leach into hot food than into cold food.

Women who are pregnant or nursing should consult with their OB/GYM prior to working in a glass studio - kiln-formed glass or stained glass.

• Heat: Scientific literature does not reveal any adverse effects in relation to working in hot environments. However, excessive heat should be avoided.
• Lactation: Exposure of a lactating woman to chemicals may also exposure the child. No danger has ever been shown to the child if chemical exposures are kept to less than the TLV, Women should avoid toxic metal exposure.
• Exertion: Pregnant women should avoid excessive exertion.
• Lead: There are many reports in the medical literature of lead exposure causing spontaneous abortions, premature deliveries and congenital abnormalities at relatively low fetal blood lead levels. Women who are pregnant or nursing should avoid all lead exposure! Women who are considering pregnancy should minimize lead exposure.
• Cadmium: Both a male and female reproductive issue. Exposure should be minimized.
• Carbon Monoxide: Relatively high exposures may result in decreased birth weight and increased  mortality of offspring. Make sure you are working in a well ventilated area.