Polyurethane Division
The Society of the Plastics Industry, Inc.
Technical Bulletin
July 1994 - AX178

Contents

Foreword
Importance of Industrial Hygiene
Selecting Personal Protective Clothing
Research Approach
Discussion Tables
Tables
Additional Information

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Foreword

This technical bulletin presents guidelines for selecting the appropriate chemical protective clothing for working with polymeric methylene diisocyanate (polymeric MDI or PMDI)* and PMDI-based foam systems. This technical bulletin analyzes and reviews performance characteristics, product availability, and costs for a variety of commercially available gloves, coveralls, splash suits and other protective suits.

Importance of Industrial Hygiene

During the handling, processing and application of PMDI, potential exposure poses distinct health and safety concerns. Contact with PMDI in vapor, liquid, or particulate form may cause a range of adverse health effects, including irritation and/or sensitization to PMDI.

Short- or long-term exposure to PMDI can affect the skin, eyes and respiratory system. Chronic dermal exposure can lead to skin irritation, skin sensitization, and may cause respiratory sensitization.

Exposure guidelines have been established to help individuals avoid overexposure and these adverse health effects. For details, see SPI Polyurethane Division Technical Bulletin AX119, "MDI-Based Polyurethane Foam Systems: Guidelines for Safe Handling and Disposal," and Technical Bulletin AX150, "Hyperreactivity and Other Health Effects of Diisocyanates: Guidelines for Medical Personnel."

Selecting Personal Protective Clothing

Individuals handling chemicals need to understand and practice safe handling techniques for PMDI and other chemicals that pose potential health hazards. This includes the wearing of the appropriate protective clothing, including eye protection (face shield or chemical worker's goggles), gloves, plus coveralls or lab aprons. This is essential to preventing skin exposure in some jobs and is strongly recommended for most individuals who work with PMDI.

When selecting protective clothing, a variety of factors must be considered. These factors include:

When the manual dexterity requirements of some jobs require the use of thin, form-fitting gloves that offer limited amounts of protection time, use of such gloves is acceptable if the gloves are changed with sufficient frequency. The protection times listed in the tables are the maximum wearing times.

The PMDI protection times referred to in this technical bulletin are based on the time required for PMDI to permeate or make its way through the chemical protective glove or garment material, and are the maximum use times. It is important for the wearer to understand the need to change gloves and garments often enough to avoid exceeding the listed protection times and to prevent contacting PMDI. For example if a job requires the use of thin, flexible gloves with a 30 minute protection time, then the wearer should change gloves within 30 minutes from initial contact with PMDI.

In addition to these factors, individual work habits, industrial hygiene practices and personal experiences will influence decisions made when selecting protective clothing.

Research Approach

The International Isocyanates Institute (III) sponsored a study whereby Texas Research Institute evaluated materials from more than 50 items of chemical protective clothing – 35 gloves of 10 different material types and 17 suits of 14 different material types – to determine the degree of resistance to permeation by PMDI that each garment offers.

The III research measured the length of time it took PMDI to permeate through the protective clothing material under conditions of continuous contact and complete surface coverage with PMDI.

The research did not address how glove and garment protection for PMDI users may be affected by solvents; nor did the research evaluate how effectively the gloves and garments protect workers against solvent exposures. It should be noted that some solvents, such as methylene chloride, are expected to quickly (<0.25 hour) permeate most of the protective clothing listed in the tables. PMDI may be carried through the garment with the solvent.

Discussion of Tables

Separate tables for gloves and body protective clothing are organized by glove or garment type, then within type are arranged by decreasing protection time. The tables also include the following information for each item: trade name, manufacturer, availability, approximate cost, thickness, and durability.

although a large number of chemical protective gloves and garments were tested, this technical bulletin is not intended to be a comprehensive review of every piece of protective clothing currently available. Other gloves and garments not included in this study may provide equivalent protection.

Individuals who work with PMDI should keep themselves informed of new protective clothing developments and consult their protective clothing suppliers and manufacturers.

PRINCIPLES OF PROTECTIVE CLOTHING SELECTION