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Standard Interpretations - Table of Contents |
| • Standard Number: | 1910.134 |
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March 1, 1989
Mr. Jay A. Parker Dear Mr. Parker: This is in response to your letter of November 4, 1988 concerning respiratory protection for mercury and chlorine. Your letter indicated that a Glendale chemical cartridge (C-27) has received an approval from the Mine Safety and Health Administration (MSHA) and the National Institute for Occupational Safety and Health (NIOSH) for protection against mercury and chlorine (TC-23C-9l6). This approval stipulates that the cartridges must be used at a belt-mounted position for continuous monitoring of the end-of-service-life indicator. You requested that the Occupational Safety and Health Administration (OSHA) accept the use of the Glendale cartridge at a face-mounted position since the Agency has permitted such application for a cartridge made by another respirator manufacturer. Upon reviewing the NIOSH test data which you submitted, we found that there is adequate service life remaining in the cartridge for the work shift after the indicator changes color. The Glendale respirator equipped with the cartridges for protection against mercury vapor and chlorine gas (TC 23C-9l6) would be acceptable for use at the face-mounted position provided that the following conditions are met in addition to the limitations which appear on the approval label: 1. The maximum use limit is up to 10 times the OSHA permissible exposure limit (PEL) for mercury and chlorine. 2. A quantitative or qualitative fit test is performed on the Glendale half-mask (F-950). 3. Monitoring of the condition of the end-of-the-service-life indicator be performed at periods of no more than 30 minutes. Please contact us if you have any questions.
Sincerely,
Mr. Edward Baier Dear Mr. Baier: Glendale Protective Technologies, Inc. recently obtained NIOSH/MSHA approval for our GR9527BM Mercury Vapor and Chlorine Respirator. The approval number is TC-23C-9l6; a copy of the approval letter is attached for your reference. As I am sure you are aware, NIOSH requirements for the mercury vapor approval state that the cartridges must contain an approved end of service life indicator [ESLI] that is visible to the wearer at all times. To achieve this, the GR9527BM has a belt-mounted cartridge arrangement. We hereby request OSHA to allow the use of our C27 mercury vapor and chlorine cartridge in a face-mounted configuration on our F950 facepiece with appropriate administrative controls that OSHA deems necessary, such as checking the indicators every half hour by looking in a mirror, or by checking the respirator in uncontaminated air. The ESLI of our C27 cartridge changes color at only a small fraction of the service life so that there is a considerable safety margin before actual breakthrough occurs [see mercury data in NIOSH letter attached]. The Mine Safety and Health Administration has already allowed such a procedure for MSA's "COMFO II" respirator with "Mersorb" cartridges [see attached memorandum], within their jurisdiction, and we will be petitioning MSHA for such treatment for our new respirator. However, there are numerous applications for this respirator within OSHA's jurisdiction, and therefore we seek to have OSHA also allow the use of the respirator in a face-mounted cartridge configuration. Please advise me in writing of your decision on this matter. Should you require any further information, please do not hesitate to contact me.
Very truly yours,
Mr. Jay Parker Reference: Your letter of August 3, 1988 Subject: Request for approval of the GR 9527BM respirator Dear Mr. Parker: Approval TC-23C-9l6 is granted to cover the GR 9527BM belt mounted respirator for respiratory protection against not more than 10 parts per million chlorine and 0.05 milligram per cubic meter metallic mercury vapor. The following limitations apply to this approval: Not for use in atmospheres containing less than 19.5 percent oxygen. Not for use in atmospheres immediately dangerous to life or health. Follow the manufacturer's instructions for changing cartridges. This respirator shall be selected, fitted, used and maintained in accordance with the Mine Safety and Health Administration, Occupational Safety and Health Administration, and other applicable regulations. In making renewals or repairs, parts identical with those furnished by the manufacturer under the pertinent approval shall be maintained. The approved assembly consists of the following Glendale parts: F-950-BM facepiece, F-36 belt mount assembly, F-37 breathing tube and C-27 (TC-23C-9l6) cartridges. These parts are to be marked with the indicated numbers in a legible and permanent manner (marking cannot be removed without evidence of its previous presence). The enclosed approval label designs are to be used in preparing the approval labels. Designs of your labels must be submitted to NIOSH for approval before printing, and proofs of the printed labels must be submitted to NIOSH for further approval before their final production. Your quality control plans for the GR 9527BM respirator were reviewed by NIOSH. On the basis of that review, your quality control plan is accepted as a part of this approval. Your drawing lists dated July 29, 1988, for the above respirators apply to this approval. This Certificate of Approval is not an endorsement of the respirator by the Mine Safety and Health Administration or the National Institute for Occupational Safety and Health, and such endorsement shall not be stated or implied in advertisements or other publicity. However, you may publicize the fact that the product has met the requirements of 30 CFR Part 11. Any changes you wish to make to this respirator shall be submitted, and a modification of this approval shall be granted before any changes are made. (Reference: Part 11, Section 11.35.) Please submit samples of respirator packaging, bearing all required labels, instructions, and markings, for our approval, before adopting them. All unused material will be discarded unless we are otherwise advised by you within seven days.
Sincerely yours,
MEMORANDUM FOR: DISTRICT AND SUBDISTRICT MANAGERS
FIELD OFFICE SUPERVISORS
FROM: ROY L. BERNARD
Administrator for Metal and Nonmetal Mine
Safety and Health
SUBJECT: Mercury Respirators
The MSA belt-mounted Comfo II respirator with Mersorb cartridges is the only
chemical cartridge respiratory currently approved by MSHA/NIOSH for mercury.
However, field use of this respirator has indicated circumstances where its
design makes this respirator inappropriate. Work situations where the
breathing tube can become a safety hazard, the work performed causes tension
on the breathing tube which can break the seal, or the breathing tube is too
short for the individual, are circumstances where MSHA will accept the
face-mounted MSA Comfo II with Mersorb cartridges provided that visual checks
of the Cartridge indicators are made every half hour, These checks can be
made by looking into a mirror or by checking the respirator in uncontaminated
air. Because leakage of mercury vapor into the respirator can not be
detected by the wearer, it is critical that a good facepiece-to-face seal be
maintained and that the indicators be monitored to prevent breakthrough
through the cartridges. If there are any questions, please Contact Margie
Zalesak (FTS 235-8307).
November 15, 1985
MEMORANDUM FOR REGIONAL ADMINISTRATORS
THRU: JOHN B. MILES Director
Directorate of Field Operations
FROM: STEPHEN J. MALLINGER Acting Director
Directorate of Technical Support
SUBJECT: Use of Chemical Cartridge respirators for Protection
Against Mercury Vapor
A chemical cartridge respirator for protection against mercury vapor
manufactured by the Mine Safety Appliance Company (MSA) has received approval
from the Mine Safety and Health Administration (MSHA) and the National
Institute for Occupational Safety and Health (NIOSH), TC-23C-629 (Mersorb).
The respirator cartridge is equipped with a passive end-of-service-life indicator (ESLI) which changes color from orange to black before breakthrough when the cartridges are installed at the belt-mounted position so the ESLI is visible to the wearer. We have received a request from MSA concerning the use of their mercury cartridges on the face-mounted position on a half-mask. MSA claims that the color indicator changes color in a much shorter time than that of the service life of the cartridge, and there is sufficient margin of safety against breakthrough even if the wearer does not perform frequent monitoring of the color change of the cartridge during the work shift. The Mersor cartridge has also received an approval for use in an environment which contains both mercury vapor and chlorine gas. We contacted NIOSH to request the certification test data. The test results indicated that when the cartridges were tested at a mercury vapor concentration of 21.5 mg/M(3) (saturation concentration at room temperature) no breakthrough (0.05 mg/M(3)) was observed after a test period of 500 to 690 minutes. The color change occurred from 31 to 305 minutes after the onset of the test. Since the mercury cartridges were tested at concentrations about 210 times the OSHA permissible exposure limit (PEL) for mercury (0.1 mg/M(3)), the actual service life would be much longer at lower concentrations. It appears that the end-of -the-service-life indicator offers sufficient margin of safety against breakthrough. In view of the above facts, it is concluded that the use of the MSA Mersorb cartridge on the face-mounted position on the half-mask would be acceptable which appear on the approval label: 1. The maximum use limit is up to 10 times the PEL for mercury vapor and chlorine gas. 2. A quantitative or qualitative fit test is performed on the three sizes of the Comfo II facepiece. 3. Monitoring of the condition of the end-of-the-service-life indicator be performed at periods of no more than 30 minutes. |
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Standard Interpretations - Table of Contents |