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NIOSH Program Portfolio

 

Manufacturing

NORA Manufacturing Sector Strategic Goals

927Z6RV - Dermal penetration of metal working fluid components

Start Date: 10/1/2006
End Date: 9/30/2009

Principal Investigator (PI)
Name: H.frederick Frasch
Phone: 304-285-5755
E-mail: hbf9@cdc.gov
Organization: NIOSH
Sub-Unit: HELD
Funded By: NIOSH

Primary Goal Addressed
9.0

Secondary Goal Addressed
None


Attributed to Manufacturing
100%

Project Description

Short Summary

The goal of this project is to obtain data on the permeation through skin of selected MWF's, using hairless guinea pig skin as a surrogate for human. Metal working fluids (MWF's) are used in the machining industry to reduce friction between the metal surface and the cutting blade. The machining process generates a fine mist that can be inhaled and deposited on the worker's skin. Occupational exposures to MWF may cause a variety of adverse dermal health effects. Metal working fluid components will be selected for study based on known or suspected potential for adverse dermal effects, including irritant and allergic dermatitis and toxicity to the body. Dermal absorption rates will be compared between new, unused fluid and used fluid obtained from an industrial machining operation.

This project relates most directly to the Manufacturing sector. The project will lead to new insight into dermal absorption and the potential for dermatitis of MWF's. Knowledge of the specific MWF components that are implicated in dermatitis, and the potential for dermal absorption of systemic toxins, will enable users of MWF to make more informed decisions regarding their use. Furthermore, it may encourage manufacturers of MWF to alter their formulation by replacing dermal toxins with less harmful components.



Description

Dermal exposures to metal working fluids occur in industrial settings. The goal of this research is to quantify the dermal penetration of potentially toxic components of metal working fluids. In-vitro skin penetration experiments will comprise the core experimental component of the project. Human surgical waste skin (panniculectomies or breast reductions) will be used. The chemical of interest will be placed on the skin membranes in our diffusion cell apparatus. The amount of chemical penetrating the skin will be monitored until a steady-state rate of absorption can be determined. LCMS or GC methods will be developed to quantify MWF components alone, in aqueous solutions, or within the MWF matrix.

The MWF components of interest will be prioritized based on 2 strategies. First, in collaboration with HELD's Allergy and Clinical Immunology Branch, chemicals will be selected based on their being known or predicted sensitizers. Results from local lymph node assays and skin sensitization predictive algorithms will be key components of this selection strategy. Second, MWF components will be selected based upon their known systemic toxicity and their predicted rate of dermal penetration. MWF candidate components will be screened through resources such as the Hazardous Substances Data Base. The predicted rate of penetration will be assessed using our previously developed models.

Dermal penetration of select MWF components will be studied from 3 vehicles: first, as their pure or neat chemical form; second, as an aqueous solution (if possible); third, from the MWF itself. The rationale here is to determine if there are vehicle effects of the MWF which enhance or inhibit the uptake of its various components.

Finally, for select MWF's, both virgin and used fluids will be examined for differences in chemical composition and dermal absorption rates. Metal working fluids are used in a continuous recirculating flow path. As they are used, they generate oxidation and other breakdown products; they take up fine metallic particles and they are supplemented with additives to inhibit microbial growth. For a select MWF, we will obtain used fluid samples from a working industrial machining operation. Composition and dermal permeation rates for these will be compared to investigate the potential for enhanced adverse effects from used MWF.



Objectives

1. New insight into dermal absorption and the potential for dermatitis of MWF's. Knowledge of the specific MWF components that are implicated in dermatitis, and the potential for dermal absorption of systemic toxins, will enable users of MWF to make more informed decisions regarding their use. Furthermore, it may encourage manufacturers of MWF to alter their formulation by replacing dermal toxins with less harmful components.

This objective will be evaluated through internet searches to assess who is using the information gained through this project.

2. Another expected outcome will be input into NIOSH's process of quantitative dermal risk assessment of MWF.

This objective will be evaluated through active participation of the principle investigator in the process of updating the NIOSH skin notations.

3. The key highlight of this project will be the dissemination of new knowledge regarding the potential for dermal uptake and dermatitis of metal working fluids to the users and manufacturers of these materials.

This objective will be evaluated through internet searches to assess who is using the information gained through this project.



Mission Relevance

Metal working fluids (MWF's) are used in the machining industry to reduce friction between the metal surface and the cutting blade. The machining process generates a fine aerosol that can be inhaled and deposited on the worker's skin. NIOSH estimates that some 1.2 million workers are potentially exposed. Occupational exposures to MWF may cause a variety of adverse respiratory and dermal health effects, with dermal exposures are most commonly associated with allergic and irritant dermatitis. In addition, MWF's contain systemic toxins for which the skin could serve as an entry portal. It is therefore important to understand the potential for dermal penetration of metal working fluid components. MWF's are proprietary formulations and most components unfortunately are not listed on Material Safety Data Sheets or other sources. Therefore the precise composition of a MWF is unknown. Recent methodological advances within NIOSH (DART) now permit the quantitative identification of MWF components. It is therefore now possible to study the skin penetration of these specific compounds, alone or within the MWF matrix. The goal of this project is to gain knowledge of the dermal penetration capacity of metal working fluids and their components. This knowledge will enhance understanding of the potential for these complex mixtures to cause allergic and contact dermatitis, and will aid in the dermal risk assessment of these fluids.

Expected users of this information will be risk assessors and regulatory officials, who can use this information to refine current policy on skin notations and dermal risk assessment. The information could potentially be used by MWF manufacturers to refine product composition through substitution of less toxic components.

This project addresses the following sector, cross-sector and coordinated emphasis area goals:

Manufacturing: Strategic Goal 9: Enhance the state of knowledge related to emerging risks to occupational safety and health in manufacturing.

Immune and Dermal Diseases: Dermal SG 1 "Contribute to the reduction of occupational skin diseases", IG 3: Develop and validate improved methodology for risk assessment of chemicals

Exposure Assessment: SG 2, IG 2.5: Conduct research on dermal absorption and dermal exposure assessment methods.

Personal Protective Technology: SG 2: Reduce exposure to dermal hazards



Page last updated: June 3, 2011
Page last reviewed: May 23, 2011
Content Source: National Institute for Occupational Safety and Health (NIOSH) Office of the Director

 

NIOSH Program:

Manufacturing