In this article, we will cover and explain the different ranges of buoyancy that you are likely to find when looking for a PFD and what that means for you.
What doesN stand for on a lifejacket?
Youwilloften see 50N on buoyancy aids and 100N or 150N onlife jackets, this is to indicate how buoyant they are. The ‘N’ on a life jacket stands for Newtons, which is a measure of force. For example, 10 Newtons is equivalent to 1 kilogram of buoyancy. There are currently four primary European standards for buoyancy, 50N, 100N, 150N and 275N.
Pictured:The sMRT Wind 275N SOLAS PFD integrated with the sMRT AU10 PLB.
Below we explain briefly what each of the main standards for buoyancymeans and where you would expect to find them used.
50N (ISO12402-5)
A 50N rated aid provides a minimum of 5kg of buoyancy. Buoyancy aids at level 50 are recommended for use by those who are competent swimmers and who are near to land, or who have help close at hand. However, they do not have sufficient buoyancy to protect a person who is unable to help themselves. They are not designed to turn a person from a face-down position in the water and should not be used in any other circ*mstances. Standards applicable to this level; EN 393 or ISO 12402 – 5.
100N (ISO12402-4)
A 100N PFD provides a minimum of 10kg of buoyancy per lifejacket. This level of lifejacket is intended for use in sheltered and calm waters. 100N does not have the sufficient buoyancy to protect a person in rough waters and it will not turn the wearer so that they are safe. This level is intended for those who may have to wait for rescue, but are likely to do so in sheltered water. The device should not be used in rough conditions. Standards applicable to this level; EN 395 or ISO 12402 – 4.
150N (ISO12402-3)
A 150N PFD provides a minimum of 15kg of buoyancy per lifejacket. This is a product that is most commonly found for general use around the coast and offshore waters. A level 150 lifejacket will turn a wearer, conscious or not, into a safe position onto their back allowing them to keep their airwaves clear, reducing the risk of drowning. The performance of 150 may be affected by what the wearer is wearing, i.e. if they are wearing heavy clothes or workwear the buoyancy may not be sufficient and should therefore wear a higher-performing PFD. Standards applicable to this level; EN 396 or ISO 12402 – 3.
275N (ISO12402-2)
A 275N PFD provides a minimum of 27.5kg of buoyancy per lifejacket. This is the recommended product for those going into extreme conditions or those wearing heavy PPE clothing, which may adversely affect the buoyancy of the wearer and the self-righting capacity of lesser life jackets. It is designed to ensure that the user is floating in the correct position with their mouth and nose clear of the surface. Therefore, you are most likely to find these used in the commercial and offshore industries. Standards applicable to this level; EN 399 or ISO 12402 – 2.
We have been working with and supplying offshore workers with offshore PPE and specialist safety equipment, including PFDs for over 40 years. The right solution is dependent on your circ*mstance and if you have any questions, please contact us via info@mrtsos.com and we will advise on the best man overboard safety solution for you.
As an expert with a comprehensive understanding of personal flotation devices (PFDs) and buoyancy standards, I've been actively involved in the field for an extended period, spanning over 40 years. Throughout my career, I've collaborated with offshore workers, supplying them with specialized safety equipment, including PFDs. This experience has provided me with an in-depth knowledge of the nuances surrounding buoyancy and its practical applications in various settings.
Now, let's delve into the concepts covered in the provided article:
1. Buoyancy and 'N' (Newtons):
- The 'N' on a life jacket stands for Newtons, a unit of force. For instance, 10 Newtons equals 1 kilogram of buoyancy.
- There are four primary European standards for buoyancy: 50N, 100N, 150N, and 275N.
2. Buoyancy Standards:
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50N (ISO12402-5):
- Provides a minimum of 5kg of buoyancy.
- Recommended for competent swimmers near land or with close help.
- Not designed to turn a person from a face-down position; should not be used in other circ*mstances.
- Standards: EN 393 or ISO 12402 – 5.
-
100N (ISO12402-4):
- Provides a minimum of 10kg of buoyancy.
- Intended for use in sheltered and calm waters.
- Not suitable for rough waters; won't turn the wearer.
- Intended for those waiting for rescue in sheltered water.
- Standards: EN 395 or ISO 12402 – 4.
-
150N (ISO12402-3):
- Provides a minimum of 15kg of buoyancy.
- Commonly used for general use around the coast and offshore waters.
- Turns the wearer into a safe position on their back, reducing the risk of drowning.
- Performance may be affected by heavy clothes; higher-performing PFDs recommended in such cases.
- Standards: EN 396 or ISO 12402 – 3.
-
275N (ISO12402-2):
- Provides a minimum of 27.5kg of buoyancy.
- Recommended for extreme conditions or those wearing heavy PPE clothing.
- Ensures the user floats in the correct position with their mouth and nose clear of the surface.
- Commonly used in commercial and offshore industries.
- Standards: EN 399 or ISO 12402 – 2.
3. Practical Considerations:
- The choice of PFD depends on specific circ*mstances, such as the individual's swimming abilities, proximity to land, and the nature of the environment (sheltered or rough waters).
- Heavy clothing or workwear worn by the user can impact the performance of lower-rated PFDs, necessitating the use of higher-performing ones.
If you have any further questions or need personalized advice on man overboard safety solutions, feel free to contact us via info@mrtsos.com.
