Minnesota Administrative Rules

5207.0303 PREENTRY PROCEDURES.

Subpart 1.

Application.

The applicable provisions of this part shall be implemented before entry into a confined space is permitted.

Subp. 2.

Disconnection of lines.

Lines that may convey flammable, explosive, toxic, or otherwise injurious or incapacitating substances into the space shall be disconnected, blinded, locked out, or blocked off by other positive means to prevent the development of dangerous air contamination, oxygen deficiency, or oxygen enrichment within the space. The disconnection or blind shall be so located or done in such a manner that inadvertent reconnection of the line or removal of the blind is effectively prevented. Code of Federal Regulations, title 29, section 1910.147, applies where lockout devices are required.

This subpart does not apply to public utility gas distribution or gas transmission systems.

This subpart does not require blocking of all laterals to sewers or storm drains. Where experience or knowledge of industrial use indicates materials resulting in dangerous air contamination may be dumped into an occupied sewer or storm drain, all such laterals shall be blocked.

Subp. 3.

Calibration of testing and monitoring equipment.

Air testing and monitoring equipment shall be maintained and calibrated according to manufacturers' instructions. This equipment shall be periodically calibrated with an appropriate test gas to ensure proper operation. Records of such calibration and field tests shall be maintained for a minimum of one year. Calibration and field test information, including type of test required, date tests were due, and date tests were completed, shall be affixed to the instrument or be readily available at the time of use.

Subp. 4.

Air tests.

The air in confined spaces shall be tested with an appropriate device or method to determine whether dangerous air contamination, oxygen deficiency, or oxygen enrichment exists before entry is made. While occupied, additional continuous or periodic monitoring for dangerous air contamination, oxygen deficiency, or oxygen enrichment shall be done. A written record of the testing results shall be made and kept at the work site for the duration of the work. Affected workers or their representatives shall be afforded an opportunity to review and record the testing results.

Subp. 5.

Injurious corrosive substances.

Workers in confined spaces that have last contained injurious substances to the eyes or body shall be provided with, and shall be required to wear, appropriate personal protective clothing or devices in accordance with Code of Federal Regulations, title 29, section 1910.132. In addition, an eyewash and safety shower as required by Code of Federal Regulations, title 29, section 1910.151, shall be provided within the work area outside of the confined space for immediate emergency use.

Subp. 6.

Interconnected spaces.

Where interconnected spaces are blocked off as a unit, each space shall be tested and the results recorded in accordance with subpart 4. The most hazardous condition found shall govern procedures to be followed.

Subp. 7.

Ventilation.

Where the existence of dangerous air contamination, oxygen deficiency, or oxygen enrichment is demonstrated by tests performed under subpart 4, existing ventilation shall be augmented by appropriate means if practical and feasible. When additional ventilation provided in accordance with this subpart has removed dangerous air contamination, oxygen deficiency, or oxygen enrichment as demonstrated by additional testing conducted and recorded under subpart 4, entry into and work within the space may proceed subject to part 5207.0304.

Subp. 8.

Ignition sources.

No sources of ignition may be introduced into the space until implementation of appropriate provisions of this part has ensured that dangerous air contamination due to flammable or explosive substances does not exist.

Subp. 9.

Oxygen consuming equipment.

Whenever oxygen consuming equipment is to be used, measures shall be taken to ensure adequate combustion air and exhaust gas venting.

Subp. 10.

Oxygen enrichment condition or use of oxygen enrichment equipment.

Whenever oxygen enrichment is possible due to conditions within the space, or oxygen enrichment equipment is to be used, measures shall be taken to ensure that the oxygen level does not exceed 23 percent in the confined space. If tests indicate the oxygen level to be greater than 23 percent, hot work is prohibited until ventilating techniques have reduced the oxygen level to less than 23 percent.

Subp. 11.

Smoking.

Smoking shall not be allowed in confined spaces or within 20 feet of a confined space opening.

Subp. 12.

Automatic fire protection systems.

Where there is no ready exit from spaces equipped with automatic fire suppression systems employing harmful design concentrations of toxic or oxygen displacing gases, or total foam flooding, such systems must be deactivated. When it is not practical or safe to deactivate such systems, the provisions of part 5207.0304, subpart 3, shall apply during entry into and work within the spaces.

Statutory Authority:

MS s 182.655

History:

23 SR 2132

Published Electronically:

June 11, 2008