OSHA's National Emphasis Program - Occupational Exposure to Isocyanates (PDF)

OSHA's Sampling and Evaluation Techniques for Aromatic Isocyanate Surface Contamination (link)

D-TAM™ Efficacy Studies (PDF)

Most Material Safety Data Sheets recommend the use of soap and water to remove toxic chemicals from the skin. Yet studies demonstrate that using soap and water is less effective in removing chemicals and may increase exposure to water insoluble (lipophilic) chemicals. This study compared the ability of water, 50% soap and water, corn oil and a polyglycol based cleaner to minimize absorption of isocyanate (MDI) into skin. The data show that corn oil (control) and D-TAM® (polyglycol based cleaner) are more effective than water or soap and water in limiting the transfer of MDI into the skin.

D-TAM™ Selection Guide (PDF)

Laboratory studies have shown that solubility is key to effective removal of chemicals from the skin. D-TAMTM Skin Cleanser and Safe Solvent are formulated with non-toxic biodegradable solvents that gently solubilize chemical contaminants on the skin and rinse off clean with water. These unique formulations of high molecular weight materials will not enhance chemical absorption into the skin. D-TAMTM products cover a broad spectrum of chemical solubilities ranging from highly oil soluble (lipophilic) chemicals to semi-polar chemicals that are somewhat soluble in water.

Chemical Exposure: Protection for First Responders and the General Public (PDF)

CLI has been researching the effects of dermal exposure and developing decontamination products and procedures for industrial use since 1990. The research and product formulation has direct applicability to the problem that the Department of Home Security (DHS) and local municipalities face in response to a terrorist attack involving chemical warfare agents (CWAs). Successful CWAs depend upon the ability to be inhaled or permeate the skin. CLI recognizes that this dependence models the same behavior that presents risk in the industrial environment from chemicals such as isocyanates and pesticides. The technology used to decontaminate exposure to these chemicals can be directly applied to decontaminate people and equipment exposed to CWAs.

Skin Exposure to Isocyanates: Reasons for Concern (link)

Isocyanates (di- and poly-), important chemicals used worldwide to produce polyurethane products, are a leading cause of occupational asthma. Respiratory exposures have been reduced through improved hygiene controls and the use of less-volatile isocyanates. Yet isocyanate asthma continues to occur, not uncommonly in settings with minimal inhalation exposure but opportunity for skin exposure. In this review we evaluate the potential role of skin exposure in the development of isocyanate asthma.

Skin Exposure to Aliphatic Polyisocyanates in the Auto Body Repair and Refinishing Industry: A Qualitative Assessment (link)

Although respiratory exposures have been the primary concern with isocyanates, skin exposure also can occur and may contribute to sensitization and asthma. Methodologies to assess isocyanate skin exposure in the workplace are limited and skin exposure data scarce. The goals of this study were (i) to evaluate and validate the isocyanate colorimetric indicators against a quantitative assay, (ii) to evaluate the extent of isocyanate surface contamination and skin exposure among auto body shop workers and (iii) to evaluate isocyanate skin exposure determinants. 

Assessing Isocyanate Skin and Surface Contamination in Car Painters Using SWYPE-RGB Analysis (PDF)

The aim of this presentation is to identify suitable methods for dermal sampling and analysis of isocyanates as well as to validate the selected method in characterizing isocyanate exposure.

 In-Use Testing and Interpretation of Chemical Resistant Glove Performance (PDF)

Issuing gloves to workers is the most common approach to protecting against skin contact with hazardous chemicals. Typically, glove materials are selected and duration of wear is estimated based on comparisons of laboratory test data. Although methods are available for assessing permeation rates during actual use, such testing is unlikely without acceptable exposure guidance criteria for decision making. This document reviews methods for testing glove performance during actual use and suggests an approach for estimating acceptable exposure guidance criteria for evaluation of chemicals that are systemically absorbed.

A Critique of Assumptions about Selecting Chemical Resistant Gloves: A Case for Workplace Evaluation of Glove Efficacy (PDF)

Wearing chemical-resistant gloves and clothing is the primary method used to prevent skin exposure to toxic chemicals in the workplace. The process for selecting gloves is usually based on manufacturers’ laboratory-generated chemical permeation data which may not reflect conditions in the workplace where many variables are encountered (e.g., elevated temperature, flexing, pressure, and product variation between suppliers). The variables that may influence the performance of chemical-resistant gloves are identified and discussed. Passive dermal monitoring is recommended to evaluate glove performance under actual-use conditions and can bridge the gap between laboratory data and real-world performance.

Determination of Alkylamine Permeation Through Protective Gloves Using Aliphatic Amine Pads (link)

A quantitative study of alkylamine permeation through a glove material using Permea-Tec aliphatic amine pads, used for the detection of chemical breakthrough of protective clothing, was performed for triethylamine following a microwave-extraction process and gas chromatographic analysis. Triethylamine exhibited > 99% adsorption on the pads at a spiking level of 729 ng (1.0 ml). Triethylamine showed recoveries from 63 to 90% (RSD < or = 5%) over the range 0.2-1.0 ml (146-729 ng) applied to pads.The quantitative concentration of triethylamine on the pads following permeation through the gloves was also determined, ranging from 101 to 103 ng cm-2 (382-386 ng per pad).

A Quantitative Study of Aromatic Amine Permeation Through Protective Gloves Using Amine Adsorptive Pads (link) 

A quantitative study of aromatic amine permeation through a glove material using Permea-Tec aromatic amine pads, used for the detection of chemical breakthrough of protective clothing, was performed for aniline following the microwave extraction process and gas chromatographic analysis. The modified ASTM F739 and direct permeability testing procedures were used to determine breakthrough times for five protective glove materials using aniline as a challenge chemical. Breakthrough times for six protective gloves were determined, ranging from 182 sec to 82 min. The quantitative concentration of aniline on the pads following permeation through the gloves also was determined, ranging from 0.53 to 0.55 mg/cm2 (1.79-1.88 mg/pad).

A Rational Approach to Skin Decontamination: Primer on Dermal Exposure (PDF)

In its National Occupational Research Agenda for the Next Century, NIOSH targeted a reduction in irritant and allergic dermatitis as a top priority. Skin disease accounts for 15 - 20% of all occupational diseases and reported incidence has increased by over 25% during the past 10 years. The standard recommended practice of using soap and water to cleanse the skin may contribute to the cycle of occupational dermatitis.

Fundamentals of Percutaneous Chemical Absorption and Decontamination (link)

Skin exposure to toxic chemicals continues to cause a range of ill health effects including irritant and allergic dermatitis, allergy and systemic toxicity. Unfortunately, there is little published data on the efficacy of skin cleansers in removing toxic chemicals from the skin. In order to develop strategies to minimize percutaneous absorption, we must start with a fundamental understanding of the skin and the dermal absorption process. By understanding this process, we can better develop effective decontamination solutions.

Isocyanate Respiratory Hypersensitivity: The Importance of Preventing Dermal Exposure

Recent studies have confirmed the inability to sensitize animals via inhalation exposure to TDI and MDI. In both studies, cutaneous (skin) contact induced respiratory sensitization in the majority of the animals. Another study concluded that the initial exposure to MDI via skin contact "may have profound effects upon the development of occupational asthma".

This research suggests that preventing skin contact with isocyanates may be of primary importance in preventing isocyanate sensitization. In the "Investigation of dermally induced airway hyperreactivity to toluene diisocyanate in guinea pigs", Bickis concluded that "the TLV should be assigned a skin notation (emphasis added) and appropriate warnings issued to all users."

 

 

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