| <<< Back to Methylene Chloride - Small Entity Compliance Guide Fact Sheets |
Printing Instructions
|
Methylene Chloride Facts No. 1
Exposure Monitoring Requirements
Occupational Safety and Health Administration (1998)
|
On January 10, 1997, the Occupational Safety and Health Administration (OSHA) issued a
standard that lowered the limit on worker exposures to methylene chloride (MC). This new
standard greatly reduces the chance of developing health problems from working in
facilities that use MC.
Worker exposures to MC occur mainly through breathing its vapors. MC can also pass
through workers' skin if it gets on their bodies or clothes. Occasionally, workers can
swallow small amounts of MC if they don't wash their face and hands before eating, or if
they eat in contaminated work areas. Short-term exposure to high levels of MC can cause
dizziness, headaches, a lack of coordination, and irritation of the skin, eyes, mucous
membranes, and respiratory system. Long-term exposure causes cancer in laboratory animals.
Studies in workers suggest an association between MC exposures and certain types of
cancer. OSHA considers MC to be a potential occupational carcinogen. Exposure to MC may
also make the symptoms of heart disease (e.g., chest pains, angina) worse.
Monitoring employee exposures to MC enables employers to identify the sources of MC and
select appropriate exposure controls. OSHA's MC standard requires that all facilities
using MC monitor employee exposures. This fact sheet provides only general information on
monitoring requirements and should not be considered to be a complete summary of the
MC-related monitoring requirements. For specific exposure monitoring requirements, please
refer to the OSHA MC standard (Title 29 of the Code of Federal Regulations, Part
1910.1052(d)). The MC standard can be accessed at
OSHA's web site.
General Requirements
If MC is used in the workplace, the employer must monitor employee exposure to MC to
determine if any employee is being exposed to MC in excess of the permissible exposure
limits (PELs): 25 ppm, as an 8-hour time-weighted average (TWA) PEL; and 125 ppm, as a 15
minute short-term exposure limit (STEL). Employers are required to conduct initial
monitoring of airborne MC concentrations and to conduct periodic MC exposure monitoring
for all tasks where employee exposures are above the action level (12.5 ppm, 8-hour TWA)
or STEL. Validated monitoring methods include OSHA Method 80 (available through
OSHA's web site), badge monitoring, and
other methods that meet the accuracy and precision requirements of the MC standard.
Initial Monitoring
- Employers with fewer than 20 employees must provide initial monitoring by February 4,
1998.
- Polyurethane foam manufacturers with 20 to 99 employees must provide initial monitoring
by December 21, 1997.
- All other employers must provide initial monitoring by September 7, 1997.
- If the applicable date stated above has passed, employers must provide initial
monitoring when MC is introduced into the workplace.
Initial monitoring is not necessary if:
- Objective data, representing the highest MC exposure likely to occur during processing,
use, or handling, show that MC cannot be released in concentrations above the action level
or STEL;
- Employee exposure monitoring was performed within 12 months prior to April 10, 1997,
which satisfies the monitoring requirements and was conducted under conditions
substantially equivalent to existing conditions; or
- Employees are exposed to MC for fewer than 30 days per year and the
employer uses direct-reading instruments to determine airborne levels of
MC. In such cases, the direct reading instruments must provide immediate
results which are sufficient to determine which measures are necessary to
control employee exposure.
Periodic Monitoring
If initial monitoring shows employee exposures at or above the action level or STEL,
employers must perform periodic 8-hour TWA or STEL monitoring as follows:
8-hour TWA monitoring:
- Every six months if initial TWA monitoring results are at or above the action level but
at or below the TWA PEL.
- Every three months if initial TWA monitoring results are above the TWA PEL.
- Periodic 8-hour TWA monitoring is not required if initial TWA monitoring results are
below the action level.
STEL monitoring:
- Every three months if initial STEL monitoring results are above the STEL.
- Periodic STEL monitoring is not required if initial STEL monitoring results are at or
below the STEL*.
If two consecutive measurements, taken at least 7 days apart, show that exposure levels
have decreased, employers may modify the monitoring requirements accordingly*.
*Those specified industries taking advantage of the new extended
compliance dates published in the revised final rule on September 22, 1998 (FR 63; 50712-50732)
must monitor STEL exposures every three months until either the date by which they must
achieve the 8-hour TWA PEL, or the date by which they in fact achieve the 8-hour TWA PEL,
whichever comes first. These specific industries include polyurethane foam manufacturing;
foam fabrication; furniture refinishing; general aviation aircraft stripping; product
formulation; use of MC-based adhesives for boat building and repair, recreational vehicle
manufacture, van conversion, or upholstery; and use of MC in construction work for
restoration and preservation of buildings, painting and paint removal, cabinet making, or
floor refinishing and resurfacing.
Additional Monitoring
Employers must perform additional monitoring if there is an indication that employee
exposures have increased. Examples include changes in the production process, control
equipment, or work practices that could increase exposure levels; and leaks, ruptures, or
other equipment breakdowns.
Monitoring Specifications
In determining each employee's workplace exposure to MC, employers may take either:
- Personal breathing zone air samples for each employee; or
- Personal breathing zone air samples for one or more employees when the samples are
representative of each employee's exposure.
Personal breathing zone air samples may be considered representative of an employee's
8-hour TWA and 15-minute short-term exposures if:
- The employee(s) sampled are in the same job classification.
- The employee(s) sampled work in the same area.
- The employee(s) sampled work during the same work shift (if the employer can document
that tasks and workplace conditions are similar during all work shifts, he/she only needs
to determine the exposure level for one work shift).
- The employee(s) sampled is expected to have the highest MC exposures of all employees in
the group of employees represented by the samples collected.
- For short-term exposures, samples are taken during operations likely to produce the
highest 15-minute exposures.
Employee Notification
Employers are required to notify employees of all monitoring results, in writing,
within 15 working days of receiving the results. If exposures are above the PEL or STEL,
the employer must inform the employee of the corrective actions being taken.
OSHA's standard requires employers to allow affected employees or their designated
representatives to observe any monitoring activities. Where such observations involve
entry into areas where personal protective equipment (PPE) is necessary, the employer must
provide and ensure the use of the appropriate PPE. In addition, the employer must ensure
that observers follow all other applicable safety and health procedures.
Recordkeeping
Employers must establish and keep accurate records of all exposure monitoring data as
well as the objective data used to support exemptions from initial monitoring
requirements.
Exposure Monitoring Data:
Employers with 20 or more employees must keep exposure monitoring records for 30 years.
The records must include information on:
- Date of the measurement for each sample taken;
- Monitored operation involving MC exposure;
- Sampling and analytical methods used and evidence of accuracy.
- Number, duration, and results of samples taken.
- Type of PPE worn.
- Name, social security number, job classification, and exposure levels (where
representative samples are used, identify all employees represented by the data and
indicate which employees were monitored).
Employers with fewer than 20 employees must also keep records for 30 years, but only
need to include information on:
- Date of measurement for each sample.
- Number duration, and results of samples taken.
- Name, social security number, job classification, and exposure levels (where
representative samples are used, identify all employees represented by the data and
indicate which employees were monitored).
Objective Data:
Objective data records must be kept as long as the employer relies on this data and
include information on:
- MC-containing material in question;
- Source of the objective data.
- Testing protocol, results, and/or analysis of the material.
- Exempted operation and data supporting the exemption.
- Other data relevant to the operations, materials, processes, or employee exposures
covered by the exemption.
Additional Resources
For more information concerning consultation assistance, contact the nearest OSHA
office (look under state listings for the Department of Labor), refer to the listings on
OSHA's web site, or contact OSHA's
Office of Information at (202) 219-8151.
|
| |
|
