SAFETY AND COMPLIANCE WITH FANS

FANS AND THEIR RISKS AND HAZARDS

The apparent problem with any fan is impeller blades that spin quickly. Moving belts, electrical risks, noise, manual handling, dust/debris/water ingress, and chemical attacks are among the others.

Let's take a look at each risk individually and see what we can do to mitigate them while still assuring worker safety and the fan's reliability.

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ROTATING IMPELLERS AND OTHER RISKY PARTS

Not only may impeller blades be dangerous, but so can drive systems and spinning shafts if they are not properly guarded or if maintenance routines are not followed. There are four critical measures to risk reduction:

1. Guarding:

Installing adequate guards that prevent unintentional contact with moving parts is one of the key strategies to limit the risks associated with rotating components. To ensure adequate protection, guards should be designed, installed, and maintained in compliance with applicable safety regulations.

2. Risk Evaluation:

To detect potential hazards related with rotating blades, belts, and shafts, a detailed risk assessment is required. This assessment aids in selecting the appropriate control mechanisms and safeguards. During the risk assessment process, it is critical to include qualified experts with knowledge in fan safety engineering.

3. Design and maintenance that is safe.

It is critical to ensure adequate fan design and maintenance. Fans should be constructed to limit operator exposure to whirling components, lowering the chance of unintentional contact. To guarantee that the rotating parts are in good operating order, regular inspection and maintenance procedures must be performed.

4. Awareness and training.

To improve awareness of the risks connected with spinning components, operators and maintenance people should be given the proper training. Personnel should be trained on safe work practices, such as lock out/tag out (LOTO) procedures, the proper use of personal protection equipment, and the significance of adhering to established safety regulations.

In most situations, the impeller is the primary source of worry, but because some fans, such as the ACI EP10A, are belt driven, guards are a significant safety factor. Notably, the EP10A has an improved design that enables the fan to be run at a reduced belt tension. This decreases the load on moving parts, which increases their longevity and reliability.

More information can be found here.

WHY IS BS EN ISO 13857:2019 IMPORTANT?

The British standard BS EN ISO 13857:2019 gives instructions for assessing and mitigating the risk of crushing or shearing risks associated with machinery. Although not particular to fans, this standard applies to many forms of machinery, including those with revolving blades, belts, and shafts.

This 32-page standard emphasizes the need of safeguarding methods such as guarding, interlocking systems, and control devices in preventing access to potentially dangerous places. It specifies the minimal distances needed to provide safe access to moving parts (taking into account characteristics such as reach, height, and speed).

By providing a systematic approach to risk assessment and control strategies, BS EN ISO 13857:2019 is a significant reference for engineers. It assists engineers in assessing the effectiveness of existing safeguards and implementing additional measures to limit the risk of accidents and injuries caused by rotating blades, belts, and shafts.

Following this criterion displays a dedication to safety. For precise specifics, it is critical to examine the standard directly and to follow its recommendations (in conjunction with other applicable industry standards and local requirements).

ELECTRICITY SAFETY HAZARDS MITIGATION

If the voltage is high enough, any electrical gadget can be dangerous. The voltage and amperage at which humans are at risk when working with electrical equipment can vary depending on a variety of factors, including:

the current flow's path

time spent exposed

Individual circumstances, such as the person's age and health.

However, certain general guidelines for electrical safety are commonly followed:

Voltages greater than 50 volts AC or 120 volts DC are generally regarded as dangerous. This is because they have the capacity to penetrate the human body's resistance (usually approximately 1,000 ohms for dry skin) and induce electric shock. Even lower voltages, however, can be dangerous in some situations, such as contact with moist or conductive surfaces.

Amperage (current) is another factor in determining the severity of an electric shock. Currents as low as one milliamp (mA) can be felt, whereas currents greater than ten milliamps (mA) can elicit muscle spasms and prevent an individual from releasing the source of electric shock. Currents greater than 100 mA can cause ventricular fibrillation, a potentially fatal heart rhythm disorder. However, the degree of the shock is also affected by factors such as exposure time and current course through the body.

It is critical to observe the Electricity at Work Regulations, the Wiring Regulations, and other relevant industry standards to maintain electrical safety.

When dealing with electrical equipment or systems, employers should give proper training, utilize appropriate personal protection equipment (PPE), apply safe work practices, and consult with experienced professionals.

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PROTECTING WORKERS FROM NOISE EFFECTS

Fans and air knives offered by ACI are designed to function at lower noise levels. Our premium LNL series has enclosures that maintain noise levels far below the 85 dB(A) standard.

Here are numerous reasons why this threshold is significant:

Prolonged exposure to excessive noise levels can lead to noise-induced hearing loss (NIHL), a chronic and irreversible disorder. Regular exposure to noise levels above 85 dBA has been demonstrated in studies to cause hearing loss over time. The laws attempt to avoid or lessen the risk of occupational NIHL by setting the upper exposure action value (UEAV) at 85 dBA.

Noise exposure and the chance of developing hearing impairment have a known dose-response relationship: as noise exposure increases, so does the risk of hearing damage. Importantly, 85 dBA is regarded as a key threshold, above which the danger of injury considerably increases.

The 85 dBA threshold for action and control of noise exposure has been widely adopted and supported by international standards organizations such as the International Organization for Standardization (ISO) and the American Conference of Governmental Industrial Hygienists (ACGIH). This consistency enables for global harmonisation and a unified approach to protecting workers' hearing health.

Considerations for Implementation - Setting the UEAV at 85 dBA strikes a reasonable balance between protecting workers' hearing and allowing for the feasibility of applying control measures. 

It is acknowledged as an attainable level that enables employers to efficiently apply engineering controls, administrative procedures, and the use of personal protective equipment (PPE) to decrease noise exposure.

It is important to note, however, that the 85 dBA level does not imply safety below that level. To further protect workers' hearing health, ongoing efforts are made to reduce noise exposure and promote the use of engineering controls such as noise isolation, damping, and source reduction.

The Control of Noise at Work Regulations 2005 (CNWR) in the United Kingdom do not specify a maximum permitted noise level in decibels. They instead concentrate on worker noise exposure and the employer's responsibility to mitigate and reduce that exposure through risk assessments, controls, and monitoring.

If noise exposure exceeds the UEAV, employers must:

identify and manage workplace noise risks

provide employees with information and training

Conduct health surveillance.

Noise reduction is achieved by opening the enclosure.

NOISE TESTS AT THE THIRD OCTAVE

Third Octave noise testing can be performed by ACI to measure and analyze sound across the frequency spectrum. The audible frequency range is divided into smaller third-octave bands in these tests. Testing offers thorough information on the sound characteristics and noise distribution at various frequencies.

The audible frequency range (often 20 Hz to 20,000 Hz) is divided into one-third octave bands in a third-octave noise test. Each band is focused on a single frequency and has a bandwidth of one-third of an octave. These bands' center frequencies are logarithmically spaced, allowing for a more detailed study of noise across the frequency spectrum.

Typically, the test is carried out with specialized sound level meters or analysers capable of detecting sound pressure levels (SPL) in each third-octave band. The sound level meter uses a microphone to capture sound and then does frequency analysis by measuring and recording SPL in each band.

The findings of a third-octave noise test are generally provided in the form of a noise spectrum table or graph. 

The knowledge is important in numerous ways:

Identifying noise sources — by examining the noise spectrum, it becomes easier to identify specific frequencies or frequency ranges where noise is more prevalent. This assists us in locating the sources of noise within a fan.

Assessing noise control methods - Third-octave noise testing can assist in evaluating the effectiveness of noise control measures by comparing the noise spectrum before and after mitigation strategies are implemented. It aids in determining the effectiveness of noise reduction initiatives across various frequency bands.

Third-octave noise testing enables reliable measurement and assessment of noise levels in compliance with certain legislation, standards, or guidelines. It provides critical data for noise impact evaluations and aids in noise limit compliance.

A table displaying the results of a fan's third octave test.