How To Ventilate Confined Spaces

Confined spaces are claustrophobic spaces that aren’t designed for humans to occupy for an extended period of time, but do allow for a worker to get into for maintenance purposes. Because human occupation is not the priority of the design, these spaces often come with potential hazards to a worker’s health such as falling, getting stuck, or dangerous levels of gas. Gases are especially difficult to account for because it can be difficult knowing how to regulate or protect from an unseen threat. To keep your workers safe, learn how to ventilate confined spaces.

OSHA Guidelines

The first step is familiarizing yourself with the OSHA guidelines found in part 1910.146. This goes over all the best practices and expectations employers must adhere to in order to provide workers with a safe environment or the personal safety equipment necessary if they must venture into a hazardous space. These guidelines apply to agriculture, construction, and shipyard employment with specific definitions of what is considered acceptable regarding confined spaces, including the protection from and regulation of gases within the confined spaces through ventilation. OSHA states “An employee may not enter the space until the forced air ventilation has eliminated any hazardous atmosphere.”

Gas Detection Equipment

The most important tool you’ll need is a confined space gas monitor. As the name suggests, it’s how you’ll check a confined space for gas hazards and identify any such related problems. These 4-gas monitors are perfect for ensuring a confined space meets acceptable OSHA conditions that determine what is considered a safe entry condition.

Because you don’t know what conditions you may be nearing, it’s a good idea to have a respirator on hand to use while testing for hazardous gases. It will protect you from accidentally breathing in unknown substances while you search and give you ample time to evacuate if you find yourself in a dangerous situation.

Concerning Oxygen

Something to be mindful of is that monitoring oxygen levels are as important as searching for hazardous gases. Too little oxygen in a confined space can lead to asphyxiation if workers aren’t able to get enough oxygen. Too much oxygen, however, can also be dangerous because of how volatile it becomes. High oxygen levels prevent a flammable and explosive hazard if so much as a spark gets into the confined space. For obvious reasons, this can cause grievous harm to your workers and further damage the inside of the confined space. The ideal oxygen level is between 19.5 and 22 percent.

Ventilation Blowers

We’re finally getting to the main event of actually learning how to ventilate confined spaces. Ventilator blowers will be your primary method of ventilation, as these are made with the express purpose of forcing air into a confined space rather than depending on natural airflow. Building vents or creating openings are inconvenient and may compromise the purpose of the confined space. Therefore, a ventilation blower is perfect for creating a non-obtrusive airflow that is removed when your workers are finished operating within the confined space.

Ventilation blowers also come in a variety of designs. For example, most blowers come in three sizes—8", 12”, and 16”—to provide a variety of airflow sizes depending on the needs and specifications of your confined space. These ventilators can be gas powered, electric powered, or DC powered and provide a range of 690 cfm to 2500 cfm. These variations are primarily for convenience, but electric blowers using an external power supply are the most common type of blower while the cubic feet per meter variants simply determine how quickly the blower will work to refresh the atmosphere. All of them will get the job done and ventilation blowers are effective at forcing air long distances such as through air ducts.

There’s an alternative to ventilation blowers—ventilation fans. These are less powerful than blowers and cover far less ground, but they are much cheaper and thus perhaps ideal if you’re looking to ventilate a confined space in a small area.

Location Considerations

You now know what necessary guidelines and requirements OSHA expect of you as well as the equipment you’ll need to fulfill those requirements. The next consideration should be the location of the confined space so that you can choose a ventilation blower that best accounts for whether the confined space is considered hazardous or non-hazardous. The National Electric Code (NEC) dictates that a hazardous confined space is one that has the possibility of fire or explosion due to the presence of flammable materials.

If a confined space is hazardous, you’ll need to provide your workers with a ventilation blower and personal protection equipment that is designed to be spark proof for these kinds of scenarios. This is to prevent the likelihood of a random spark from setting the confined space ablaze, and ventilation blowers built for these hazardous conditions are made with an explosion-proof motor. What explosion proof means in this context, however, is that the engine is designed to have an emphasis on sturdier structural integrity to contain any explosions that happen within the motor. This caveat is important to remember because there’s no such thing as “true” explosion proofing, and the same precautions should be practiced even with reduced risks.

What Workers Should Know

A well-trained and well-informed crew is crucial. All the protective equipment and preventative measures in the world are rendered moot in the face of human error. To prevent such a variable, it’s necessary for your workers to be properly trained on how to handle and operate the equipment as well as how to perform best practices for the safest environment possible. Thus, OSHA has decreed that workers have a right to the following:

• Working conditions that do not pose a risk of serious harm.
• Receive information and training (in a language and vocabulary the worker understands) about workplace hazards, methods to prevent them, and the OSHA standards that apply to their workplace.
• Review records of work-related injuries and illnesses.
• File a complaint asking OSHA to inspect their workplace if they believe there is a serious hazard or that their employer is not following OSHA rules. OSHA will keep all identities confidential.
• Exercise their rights under the law without retaliation, including reporting an injury or raising health and safety concerns with their employer or OSHA. If a worker has been retaliated against for using their rights, they must file a complaint with OSHA as soon as possible, but no later than 30 days.

Transparency of potential hazards and consistency of policies will make for effective safety practices and procedures. Workers should be encouraged to ask questions or ask for clarification. After all, well-informed workers are key to preventing mistakes that lead to injury.