Since prehistoric times, information about the materials used in products such as medicines and dyes has been shared between manufacturers and end users. Now, we have regulations and standards from OSHA, ANSI and GHS to contend with.
The roots of material safety data sheets (MSDS) can be traced to prehistoric times, when information about materials used in medicines and dyes was exchanged verbally. The first written MSDS were found on papyrus rolls in the tombs of the ancient Egyptians.
By the mid-20th century, however, these documents had evolved into a means for manufacturers and trade groups to voluntarily provide information on how to safely use their materials.
Today, MSDS contain information prescribed by law, and are administered in the United States by OSHA as part of 29 CFR 1910.1200, the hazard communications standard. The primary purpose of this standard is to identify and communicate the potential hazards of workplace chemicals. Under this standard, most solid gaskets and other sealing products fall under the classification of “articles” as defined in paragraph (c):
“Article” means a manufactured item other than a fluid or particle: (i) which is formed to a specific shape or design during manufacture; (ii) which has end use function(s) dependent in whole or in part upon its shape or design during end use; and (iii) which under normal conditions of use does not release more than very small quantities, e.g., minute or trace amounts of a hazardous chemical (as determined under paragraph (d) of this section), and does not pose a physical hazard or health risk to employees.”
Since the standard was issued in 1983, MSDS have become instruments of commerce. Even though articles and non-hazardous substances are exempt from the standard, MSDS for them have become a prerequisite for conducting business in many sectors, including the sealing industry. Most gasket and seal manufacturers provide MSDS for many of their products, either on their Web sites or on request. Interestingly, MSDS often are requested even for gaskets and seals that conform to regulations pertaining to contact with food (FDA), water (NSF) or pharmaceuticals (USP).
Unlike regulations in some countries, 29 CFR 1910.1200 does not specify a chronology for updating MSDS, nor does it specify a format. Many companies follow ANSI Z400.1 — 2004, American National Standard for Hazardous Industrial Chemicals — Material Safety Data Sheets — Preparation.
ANSI Z400.1 — 2004 AND MSDS
This is 16-part format aligns with the Global Harmonized System (GHS) set to replace the various classification and labeling standards of different countries.
Section 1, Product and Company Identification, links MSDS to the material label, identifies the manufacturer of the material and identifies a source for more information.
Section 2, Hazard Identification, provides an emergency overview, including physical properties, as well as significant physical hazards. It lists potential adverse human health effects and symptoms that might result from reasonably foreseeable use and misuse of the material and potential environmental hazards. It also lists OSHA regulatory status.
While an “article” may not be considered hazardous under normal conditions of use, the product still may pose a hazard under certain conditions. The most significant acute hazard that can occur with many gaskets and sealing materials is the generation of toxic vapors as a result of thermal decomposition. This is common to products containing such widely used polymers as polytetrafluoroethylene (PTFE), acrylonitrile-butadiene (NBR) rubber, fluoroelastomers (FKM) and silicone. Rarely are physical properties posing hazards such as fire, explosion and chemical reactivity found at significant levels in gasket and seal compositions. However, they may contain fillers and fibers that — if they become airborne at respirable dimensions — can pose potentially adverse effects on human health.
Section 3, Compositional Information, lists OSHA hazardous components, non-hazardous components and additional information about components.
Most gasket and sealing compositions are assumed to pose the same hazard as any component in them in concentrations above 1 percent (0.10 percent for carcinogens) that could be released, exceeding established OSHA exposure limits, ACGIH threshold limit values or that could present a health risk to employees. A health hazard is defined as a substance for which there statistically is significant evidence, based on at least one study conducted in accordance with established scientific principles, that acute or chronic health effects may occur in exposed employees.
It is not uncommon for many widely used gasket and sealing materials to contain some level of hazardous or carcinogenic substances. Carbon black, the primary filler in most black elastomeric compounds, is a prime example. Classified by the International Agency for the Research on Cancer (IARC) as Group 2B (possibly carcinogenic to humans), it does not pose a risk when it remains bound within a product matrix such as rubber.
Another common example is crystalline silica, a basic component of soil, sand, granite and many other minerals and classified by the IARC as a Group I carcinogen. Not surprisingly, it is found in low concentrations in many naturally occurring materials used in gaskets and seals, such as kaolin clay and graphite. It also is used sometimes as filler. As with carbon black, it poses health issues only when it is airborne and of respirable dimensions.
Many gasket and seals also contain Inconel or stainless steel reinforcement. Such alloys contain significant amounts of metallic elements such as nickel and chromium, which can be hazardous. Again, the hazard exists only when abrasion generates particulates or overheating produces fumes. Nickel also can cause allergic skin reactions, but in most gasket and sealing materials, such reinforcement is imbedded in the product so exposure is unlikely.
Section 4, First Aid Measures, provides instructions if accidental exposure requires immediate treatment and instructions for healthcare professionals.
Section 5, Fire Fighting Measures, provides basic fire fighting guidance, including suitable and unsuitable extinguishing media, while Section 6, Accidental Release Measures, provides actions to minimize adverse effects of an accidental spill, leak or release of the material.
Section 7, Handling and Storage, includes information on appropriate practices for safe handling and storage. This is a very significant section relative to many gasket and sealing compositions. Activities that generate dust, such as grinding or cutting using power saws, should be avoided.
Where dust and debris have been generated, they should be wet-wiped or vacuumed with HEPA filtration-equipped vacuum cleaners. They should not be dry-swept or blown with compressed air.
In addition, fluorinated polymers such as PTFE or FKM elastomers may generate hydrofluoric acid upon thermal decomposition.
Section 8 covers exposure controls and personal protective equipment. It provides exposure guidelines, information on practices and/or equipment for minimizing worker exposure and guidance on PPE.
Section 9, Physical and Chemical Properties, contains data, including fire and explosive properties, that can be used to characterize the material and design safe work practices.
Section 10, Stability and Reactivity, discusses conditions or materials that affect the hazards and/or intrinsic stability of the material, as well as product decomposition resulting from storage or handling.
Information in this section describes circumstances that could result in a hazardous chemical reaction. It details what media or chemicals successfully can be contained by the gasket or seal.
Section 11, Toxicological Information, provides toxicological information on the material and/or its components, while Section 12, Ecological Information, contains ecotoxicological information on the material and/or its components. It also provides environmental fate information on the material and/or its components.
Section 13, Disposal Considerations, provides information for determining appropriate disposal measures for the material and/or its containers. Section 14, Transport Information, contains basic shipping classification information.
Section 15, Regulatory Information, contains information on regulations affecting the material, whileSection 16 provides additional information that may be useful. This includes hazard rating and rating system, preparation of revision information and label information.
HAZCOM AND GHS
On Sept. 30, 2009, OSHA released its proposal to modify the current hazard communication standard to conform to the United Nations' Globally Harmonized System of Classification and Labeling of Chemicals (GHS). This worldwide system for standardizing and harmonizing the classification and labeling of chemicals is designed to:
- Define health, physical and environmental hazards of chemicals.
- Create classification processes that use available data on chemicals for comparison with the defined hazard criteria.
- Communicate hazard information and protective measures on labels and material safety data sheets.
Under GHS, MSDS simply will be referred to as safety data sheets (SDS). Based on what has occurred to date, the GHS likely will result in greater similarity among SDS from various locations, but some regional or country-specific variations will remain. The status of gasket and sealing materials as “articles” does not appear to be affected under the proposed regulations. The regulation specifies a 16-part format, similar to that specified by ANSI Z400.1 — 2004, but sections 12 through 15 are not mandatory.
OSHA estimates a minimum of 18 months from the Notice of Proposed Rulemaking before the final rule is promulgated. Companies then will have 3 years to comply with the final rule and 2 years to implement training requirements on the final regulation. Once the rule is final, companies can begin implementation.
However, in accordance with a letter of interpretation from OSHA on Oct. 6, 2009, companies can begin following the EU GHS label format for their OSHA labels as long as the labels also comply with the current hazard communication standard. For more information relative to GHS, visit http://www.osha .gov/dsg/hazcom/global.html.
Michael McNally is a senior chemist with Garlock Sealing Technologies in Palmyra, N.Y.