Protection strategies for confined work areas

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According to recent statistical data, over half of all major occupational poisoning incidents in recent years have occurred in enclosed work areas. There are certain objective reasons for the high frequency of accidents: enclosed spaces contain many potential hazards, and it is difficult for workers working there to maintain contact with the outside world. However, the main reason for the frequent accidents is that the relevant companies fail to predict dangers in advance and take preventive measures. Part 1: Definition of “confined space”. What is a confined space? A confined space refers to a place that is not used or occupied frequently, poses potential hazards, and makes it difficult for people to escape in case of an emergency. ?Common confined spaces include: reaction vessels, tanks and cabinets, air conditioning units, large drums, pipes, drainage pipes, boilers, sewers, and ditches. Definitions of qualified personnel and supervisors: Qualified personnel refer to those who are capable of identifying hazardous working environments and have the authority to take appropriate measures to reduce the level of danger in such environments. Guardian: refers to the person who stays at the entrances and exits of a confined workspace to oversee activities there while the people working inside are carrying out their tasks. Part Two: Responsibilities Responsibilities of safety management personnel: Responsible for overseeing other departments and employees to comply with the operating procedures for work in confined spaces. Classify each person who needs to enter a confined space. Train the relevant responsible persons and qualified staff so that they understand the procedures for entering confined work areas and the responsibilities they need to assume. Review, inspect, and select safety equipment, instruments, and personal protective equipment. Responsibilities of the operating department or contractor supervisor: The person in charge of the operators and the contractor supervisor shall ensure that the workers comply with and follow the procedures for working in confined spaces. Determine the work tasks and apply for a permit to enter confined spaces; keep up-to-date documents related to confined spaces. Responsibilities of qualified personnel: Before entering a confined space, assess existing and potential hazards; train all persons who may enter the space for work or carry out emergency rescue; use appropriate gas detection equipment to monitor the atmospheric conditions in the confined space, and ensure that such equipment is maintained and calibrated; if harmful gases are present in the confined space, immediately inform safety personnel. After understanding the conditions inside the confined space, apply for a permit to enter it; guide workers on how to wear and use personal protective equipment as required; assign trained supervisors to monitor the work process; follow established procedures to guide workers in carrying out their tasks or to execute the relevant procedures themselves. Only after confirming that all personnel have left the space can it be restored to its normal state and put back into use. Responsibilities of supervisors: Maintain communication with the people inside the confined space to stay informed about the progress of work and the condition of the personnel; carry communication devices and ensure they are in good working order; seek assistance immediately in case of an emergency; during supervision, do not enter the confined space unless there are other trained personnel available to take over supervision duties. Responsibilities of operators or contractor employees: All operators and contractor employees must comply with the procedures for working in confined spaces. In addition, they have the following responsibilities: Do not enter a confined space without proper authorization; use safety equipment and wear personal protective equipment correctly, in accordance with the training received. Part 3: Hazard assessment of confined spaces. If there are unsafe factors in a confined space, one should not enter it blindly. The situations that exist are as follows: Areas with insufficient oxygen levels pose a risk of electrical injuries; areas with mechanical hazards present a risk of falls; areas filled with loose particles, liquids, and other objects pose a risk of suffocation; areas containing explosive, flammable, or toxic substances; areas with poor access for entry and exit; areas where welding, cutting, burning, spraying operations must be carried out, or where chemicals must be used.

**Part IV: Procedures for Working in Confined Spaces**
**I: Preparation Phase**
(a) **Preparation before entry**
Determine whether special procedures are required, such as welding. Clear the passages in the confined space. Isolate it to prevent harmful substances from entering external systems, including pipelines, process systems, emission systems, and plant facilities. Prepare all necessary safety equipment. Ventilate the confined space first, then monitor the following parameters:
– Oxygen level: 19.5% to 23.5%
– Lower explosive limit: For vapors and dusts that pose an explosion risk, this value must be zero.
– Concentration of toxic substances: There should be no toxic substances at levels above the permissible limits.
Continuous monitoring: Safety officers should decide whether continuous monitoring is necessary based on the actual situation. Monitoring for the next shift: If work in the confined space needs to continue into the next shift, the air quality must be checked again before work starts in that shift.

(b) **Preparation by the permit issuer**
1. The permit issuer must be an authorized person who checks the preparation work before starting the operation. This includes understanding:
– What work will be done in the confined space.
– Who will enter the confined space.
– Who will be responsible for rescue and supervision.
– What conditions may arise in the confined space.
– How to handle emergencies.
– How to report emergencies.
2. The permit issuer must ensure that the permit is displayed at: the entrance to the confined space (original copy), and at the offices of operators and contractors (copy), as well as at the offices of safety officers (copy).

(c) **Training preparation**
All employees and supervisors who need to enter the confined space must receive emergency rescue training. Those who use gas detectors must also receive appropriate training.

(d) **Minimum requirements**
The confined space must have good air circulation. Contractors and supervisors are responsible for reporting any unsafe conditions immediately. People entering the confined space must carry flashlights. Operators must consult the permit issuer regarding the special requirements for welding, cutting, etc. They must also ask about the special requirements for using and handling chemicals in the confined space, as well as for using equipment such as grinders, drills, and sanders.

**II: Execution Phase**
It is not allowed to enter a confined space until all preparation work is completed and it can be confirmed that the working environment meets safety standards. A work permit must be obtained before entry. Before entering the confined space, operators or contractors must identify and mark potential hazards. Work can only proceed when there is someone to supervise. Low-voltage systems or grounding measures must be used to reduce the risk of electric shock ； When entering work areas where there is a risk of fire or explosion, explosion-proof electrical equipment must be used. Safety managers must inform other personnel, through signs, notices, or other means, that someone is working in confined spaces. In the event of an emergency, the person who issued the permit or the safety officer must immediately stop all activities in those confined spaces. At shift changes, safety managers and the qualified personnel of the next shift should reissue the permit, recheck the air composition, and record relevant information related to the permit (note: this procedure must be repeated for each subsequent shift). After each shift, the operator or contractor should collect both the original and copies of the permit ； After all work is completed, return the permit to the safety officer for archiving. If further access to the confined space is required, a new permit must be applied for. Upon completion of the work, qualified personnel must check and verify that all people and equipment have been removed from the confined space, and then hand over the issued permit to the safety officer for archiving.

Part 5: Safety Equipment Required for Entering Confined Spaces
1. Common safety equipment
- Safety belts: equipped with hooks, connectors, and lifeline ropes.
- Self-contained breathing apparatus (at least two sets).
- Fire extinguishers, when flammable materials are to be used.
- Emergency escape breathing devices (the appropriate model depends on the specific circumstances).
- Elevators and rope ladders for emergency rescue.
- Gas detection instruments.

2. Personal protective equipment
- Head protection: Safety helmets must be used and worn if there is a risk of head injury in the confined space.
- Eye protection: Safety glasses with side shields must be worn throughout the process.
- Hearing protection: Workers must wear hearing protection when the noise level in the confined space exceeds 85 decibels.
- Respiratory protection: Workers must wear respiratory protection when there are toxic or harmful dusts or particles in the confined space.
- Hand and body protection: Gloves and protective clothing should be used when performing tasks such as cutting or welding.
- Foot protection: Safety shoes must be worn.
- Fall protection: Full-body safety belts with shock-absorbing ropes should be used; guardrails and safety nets should be considered when working at heights of more than 1.8 meters.
- Detection instruments: Portable gas detectors.

3. First aid equipment
- Lifeline ropes
- Full-body safety belts
- Self-contained breathing apparatus
- Long-necked breathing apparatus
- First aid safety belts
- Triangles, ropes, and pulleys

4. Other safety equipment
When the use of certain special equipment is required, it must be used in accordance with the requirements specified in the permit, and relevant training must be provided to the workers. Standard equipment includes: ventilation systems, communication tools (horns, whistles, telephones, walkie-talkies, etc.), explosion-proof lighting and electrical equipment, safety warning tapes, and isolation devices. Contact number: 021-64398971. Contact person: Liu Xingliang; Technician: Zhao Jiabin. Shanghai Hangli Industrial Co., Ltd