How an MSDS Can Be a Useful Tool

Although the MSDS has shortcomings, it is still an important tool for people involved in construction. If you are not working with a physician/architect team knowledgeable about chemicals, the MSDS can be confusing to interpret. However, the MSDS may provide useful information when used in conjunc­tion with other tools. The National Institutes of Healths National Library of Medicine has developed a searchable database for a wide variety of household product information.5 The database can be searched by product, in­gredients, and MSDS. By comparing MSDS chemical lists with the information available through the library, it is possible to gain a bet­ter understanding of recognized potential hazards for the listed chemicals.

Certain rules of thumb can also be used to evaluate a chemical listed in the MSDS. For example, if no special precautions are re­quired when using the chemical, if there are no listed health effects, and if cleanup in­volves only water, you might assume that the chemical in question has relatively low toxic­ity. On the other hand, if it is recommended that you wear gloves and goggles and use a respirator in a well-ventilated area, the prod­uct is likely a health hazard at least while being applied, though it may not have detrimen­tal health effects once fully cured. Certain chemicals should pique your concern, such as chlorinated or fluorinated compounds and chemicals that contain toxins such as tolu­ene, phenol, benzene, xylene, styrene, formal­dehyde, and the heavy metals, to name just a few.

With more than 88,000 chemicals in com­mon use and no toxicity data on most of them, our evaluation can be only partial at best. The US Environmental Protection Agency has published a list of 53 chemicals that ranked highest as persistent, bioaccumulative, and toxic compounds, or PBTs.6 The California Of­fice of Environmental Health Hazard Assess­ment has published a list of chronic exposure levels for 80 common chemicals.7 Lists such as these are far from comprehensive and they cannot help us choose products with certainty. They can, however, help us to identify known hazardous chemicals and exposure levels and to reject products that contain these.

In summary, although you cannot base your decisions solely on information from the MSDS, it is nevertheless useful. Below are two MSDS examples, with product and manufac­turer names omitted. Because MSDSs do not always follow a consistent format, compari­sons can be difficult. Section numbers will vary, but the information covered remains the same. While the MSDS for Product #1 is in­dicative of a product that may be safe to use and in fact is one we recommend to our cli­ents, Product #2 has an MSDS that provides cause for concern.

Product Identification

This section includes the name of the prod­uct, the manufacturer, the date the MSDS was prepared, and the preparer s name. In the first sample MSDS, the product is a wood pres­ervative. The second sample involves a foam insulation material. As seen in the examples, product information may range from very lit­tle to substantial.

Material Safety Data Sheet
Section 1 -— Product Identity	Manufacturer’s Name:
Date Prepared:
Preparer’s Name:
Chemical Name: Water-based wood preservative	Product:
Chemical Formula: N/A (product is a mixture)	Product Identification No.:
DOT Shipping Class: Not regulated
Emergency Telephone Number:

Product # 2 TABLE 1.2 Material Safety Data Sheet Manufacturer: Date Prepared: Telephone Numbers: Emergency Number: Technical Information: Regular Business Hours:

Material Identification and Hazardous Components This section lists the chemical names of all product ingredients found to be reportable health hazards. Exposure limits in some in­stances are established by government agen­cies. As discussed earlier, OSHA PEL refers to the permissible exposure limits set by OSHA and ACGIH TLV refers to the threshold limit values set by the American Conference of Governmental Industrial Hygienists. These values are updated on a regular basis.

If you are not familiar with the toxicity of the chemicals listed and you have no refer­ences available on the subject, you can infer this information by examining the limits set by the government. When the limit is in parts per million, you can be sure that the product is highly toxic. NE stands for no established limit, and could mean either that adequate testing has not been performed or that the product is not considered highly toxic.

With a health rating of і, flammability and reactivity levels of o, and no established expo­sure limits, we can assume that the ingredients in this product are relatively safe.

In the second sample MSDS, the chemi­cals 4,4-diphenylmethane diisocyanate and chlorodifluoromethane (HCFC-22) are lim­ited to parts per million. Both chemicals are in fact known to be extremely toxic. With pro­longed or repeated exposure, diisocyanates and halogenated hydrocarbons can damage

Section II — Hazardous Ingredients
Hazardous Components (Special Chemical Identity/Common Names)*	CAS#	Wt. %	OSHA PEL	ACGIHTLV
Propylene glycol	57-55-6	30-50	None established	None established
Polyethylene glycol	25322-68-3	30-50	None established	None established
Disodium octaborate tetrahydrate	12008-91-2	20-30	15 mg/m3 (dust)	10 mg/m3 (dust)

* Denotes a toxic chemical reportable under SARA Title 111 Section 313, Supplier Notification provision HMIS Information: Health:!; Flammability: 0; Reactivity: 0

Product #2 TABLE 1.4

Section II — Hazardous Ingredients/ldentity Information
CHEMICAL NAME	CAS NO.	OSHA PEL	ACGIHTLV	PERCENTAGE
Polyurethane resin	NE*	NE*	NE*	50-85
4,4-diphenylmethane diisocyanate	101-68-8	0.02 ppm CEIL	0.005 ppm TWA**	5-15
Chlorodifluoromethane (HCFC-22)	75-45-8	1,000 ppm TWA**	1,000 ppm TWA**	15-25

*Not established **Time-weighted average Hazard Rating: Health: 3; Flammability: 0; Reactivity:!

the nervous, immune, and endocrine systems. Note that the health hazard rating is 3 out of a possible 4.