Safer alternatives for solvents containing methylene chloride to prevent central nervous system impairment or death.
Hazard Analysis — Interaction with paint-related solvents
Workers who refinish bathtubs may face hazards from interaction with paint-related solvents. Some of the most commonly used solvents for paints are aliphatic hydrocarbons or other petroleum distillates.
Petroleum distillates used in painting tasks may cause skin irritation, a condition also known as irritant contact dermatis (ICD). One of the most commonly used class of paint solvents are aliphatic hydrocarbons, also called petroleum distillates.
Petroleum distillates in increasing order of boiling point are gasoline, benzene (VM&P Naphtha), mineral spirits (Stoddard solvent, odorless mineral spirits, turpentine substitutes and white spirits) and kerosene.
Petroleum distillates, which tend to be less toxic than most other solvents, are still skin irritants which can cause irritant contact dermatitis (ICD). ICD is a non-immunologic reaction that manifests inflammation. Signs of ICD include stinging, blisters, dead skin, flaking scabs, scaling, cracks, redness, swelling, bumps and dryness. Itching is common, and there is often pain in the affected areas. Anyone who has contact with skin irritants can get ICD. In most cases, ICD clears up when the skin no longer contacts the irritant.
Furthermore, normal mineral spirits has about 15-20% aromatic hydrocarbons which are known to cause destruction to bone marrow and leukemia. Odorless mineral spirits and turpentine substitutes have these more toxic aromatic hydrocarbons removed, and are recommended as substitutes for regular mineral spirits and turpentine.
Methylene chloride (dichloromethane or DCM) is another paint-related solvent primarily used as a paint stripper. Its application is intended for improved adhesion on oily or greasy surfaces such as bathtub refinishing. It is also a skin and eye irritant however, unlike most paint-related solvents, most of the chemical enters the body through inhalation. It is metabolized in the liver to form carbon monoxide in the blood, carboxyhemoglobin, reducing the ability of the blood to carry oxygen causing asphyxiation. Inhalation of DCM at high concentrations can also impair the central nervous system causing confusion, dizziness, drowsiness, confusion, headaches, nausea and decreased visual, auditory and motor functions. OSHA considers methylene chloride to be a potential occupational carcinogen.
Level of Risk:
The skin is an important route of exposure to chemical agents. Although there are limited studies on ICD in the construction industry, the U.S. Bureau of Labor Statistics reports that occupational skin diseases, including ICD and allergic contact dermatitis, are the second most common type of occupational disease. From 1983 to 1994, the rate of occupational skin diseases increased from 64 to 81 cases per 100,000 workers. In 1994, there were approximately 66,000 reported cases of occupational skin diseases, accounting for about 13% of all occupational diseases. Moreover, occupational skin diseases are believed to be severely underreported, such that the true rate of new cases may be many fold higher than documented.
National Occupational Research Agenda (NORA): Priority Research Areas . Allergic and Irritant Dermatitis.
There are some measurement tools to indicate the risk for dermatitis in this task, where skin contact with paint-solvents is common, that include observation to see how frequent skin contact occurs and asking workers about skin symptoms.
For paint-solvents like DCM, the risk serious illness or death is also dependent on space enclosure and number of ventilation sources when a worker does not have supplied-air.
Here are some tools you can use to measure the risk for dermatitis, and find ways to reduce the risk. You might also think of other tools.
- Observations and reports of work/personal practices
- Symptoms checklist
Consider comparing your group of workers with themselves before and after beginning a program to reduce dermatitis. Use written checklists. Watch your employees' work practices and take reports from them of what they do with a before and after comparison. Which best practices are the employees currently doing? Which are they failing to do? Keep a written record of observations. Have employees complete a symptoms checklist of the skin problems they currently have, with no names attached. Ask them to do a pH test of surface skin. Once you have a baseline record, then begin the effort to reduce skin problems. Take the same measurements periodically to assess progress. The results can help you adjust the efforts.
Best Practices Checklist
___ 1. Wash with clean running water and pH-neutral soap.
___ 2. Wear correct gloves.
___ 3. Wash before putting on gloves.
___ 4. Wash again whenever gloves are removed.
___ 5. Use disposable gloves or clean reusable gloves daily.
___ 6. Remove gloves properly.
___ 7. Wear glove liners.
___ 8. No jewelry at work.
___ 9. Long sleeves buttoned or taped inside gloves.
___ 10. Rubber boots with pants taped inside for concrete work.
___ 11. Never let cement remain on skin or clothes.
___ 12. Avoid barrier creams
___ 13. Avoid skin softening products at work.
___ 14. Change out of work clothes before leaving jobsite.
___ 15. See a doctor for any persistent skin problem
___ 1. Check if you had at least one skin problem during the last 12 months
___ 2. Check if you currently have the skin problem.
___ 3. If you have a skin problem, check all the words that apply
___ scaling or peeling or dead skin
___ other (describe):
Worksite conditions can determine whether a worksite material will cause skin problems.
- How long does the material contact the skin?
- How often does a worker use the material?
- Is there mechanical trauma or abrasion of the skin (a break in the barrier)?
- Is the material trapped or occluded to the skin with gloves, creams, lotions, petroleum jelly, or barrier creams?
- Are there adequate hygiene facilities?
Environmental factors can cause skin problems directly or they can work with other factors to increase skin problems:
- Heat causes sweating. Sweat dissolves chemicals and brings them into closer contact with the skin. Heat increases blood flow at the skin surface and increases absorption of materials into and through the skin.
- Cold dries the skin and causes microscopic cracks. Cold changes blood flow at the skin surface and leads to loss of feeling.
- Humidity increases sweating. High humidity keeps sweat from evaporating. Extremely low humidity can dry skin as sweat evaporates.
Individual factors can affect work-related skin problems. These include:
- Pre-existing dermatitis
- Genetic predisposition
- Personal behavior/workpractices
Regulations & Standards:
OSHA standard 1926.28, titled Personal Protective Equipment, in safety and health regulations for construction must be in place. The employer is responsible for requiring the wearing of appropriate personal protective equipment in all operations where there is an exposure to hazardous conditions or where this part indicates the need for using such equipment to reduce the hazards to the employees.
OSHA standard 1926.59, titled Hazard Communication, in safety and health regulations for construction must be in place. The purpose of this section is to ensure that the hazards of all chemicals produced or imported are evaluated, and that information concerning their hazards is transmitted to employers and employees. This transmittal of information is to be accomplished by means of comprehensive hazard communication programs, which are to include container labeling and other forms of warning, material safety data sheets and employee training.
Regulations adopted by a state must be at least as protective as the corresponding federal standard. Work may also be subject to rules of other federal, state and local agencies. Even where there is no hazard specific standard, OSHA prohibits employers from to work in surroundings or under working conditions which are unsanitary, hazardous, or dangerous to his health or safety.
Federal OSHA Standards are enforced by the U.S. Department of Labor in 26 states. There are currently 22 states and jurisdictions operating complete State plans (covering both the private sector and state and local government employees) and 5 - Connecticut, Illinois, New Jersey, New York and the Virgin Islands - which cover public employees only. If you are working in one of those states or jurisdictions you should ensure that you are complying with their requirements.
The Last Planner® System is a production planning and control system designed to produce predictable work flow and improve project performance across the design, construction and commissioning stages of construction projects.