My right foot is jealous of my left foot. When one advances, the other wants to pass it. And I, like a fool, walk!
Raymond Devos
What is it about?
When we get up in the morning, we put on our slippers and leave them a little later to put on shoes before going to work. But, let’s ask ourselves: what are shoes really for? Are there specific shoes for certain activities? What are overshoes or overshoes?
What is a shoe?
The Larousse dictionary gives us the following definition:
Shoe: object of leather, leatherwork, fabric, plastic materials, intended to dress the foot and possibly the leg.
The shoe protects the foot during the walk for the displacements. To simplify, a shoe is composed of the upper, a set of components of the upper of the shoe, and the sole which protects the sole of the feet. When the upper covers the leg (and maintains the ankle) we speak of boots.
History
The first shoes appeared in the fourth millennium B.C. They were composed of a piece of leather sewn to cover the forefoot like a moccasin. Ötzi, the cold mummy called “The Iceman”, dated to 3300 BC, also wore this type of shoe.
Shoes are an integral part of the history of costume. They reflect the social status of the person wearing them. Marie Antoinette owned no less than 500 pairs of shoes! Some people use them as a marker of identity, for example the TV presenter Nagui likes to wear crazy shoes, but not just any shoes: Louboutins at 1,000 euros a pair!
Why shoes?
Shoes are adapted to their use: for example we distinguish
– shoes called “city shoes” intended to be worn outside in everyday life (generally differentiated between men’s shoes and women’s shoes);
– light shoes such as sandals, espadrilles and other barefoot shoes;
– indoor shoes (slippers, charentaise…);
– sports shoes (sneakers, walking shoes, rangers…);
– orthopedic shoes…
How is a shoe made?
The upper is a complex part composed of several materials ensuring strength, breathability and water resistance.
The sole provides grip on the ground while ensuring cushioning comfort and stability to the wearer. It can be composed of 3 different materials constituting 3 parts: the outsole in contact with the ground, the midsole providing cushioning and the removable insole for comfort.
Safety or protective footwear
Professionals are equipped with safety or protective shoes. They are intended to protect the feet in professional environment where the risks are numerous and can generate serious pathologies like fractures, sprains and other burns…
Safety shoes are complex products combining safety, comfort and aesthetics. They are adapted to the specific protection against various dangers.
° Mechanical risks (cuts, fall of heavy loads, perforation…); to protect against falls of heavy objects on the toes, accessories such as toe caps are added inside the upper.
° Risks related to movement (falls, slipping, etc.); slipping: anti-slip sole, walking on sharp objects: anti-perforation sole.
° Thermal risks (cold, heat, fire, molten metals…); ambient cold: anti-cold sole and padded upper, ambient heat: anti-heat sole, molten metal projection: adapted resistant upper, fire fighting: resistant upper and sole.
° Electrical risks (live conductors, electrostatic discharges, etc.); electric arc: insulating shoes, electrical contact: antistatic soles, electrostatic discharge: conductive soles.
° Chemical risks (toxic, corrosive liquids, etc.); acids, bases, solvents, hydrocarbons: resistant and waterproof upper and sole
° Biological risks (irritations, allergies, pathogenic germs…), antimicrobial stems.
Overshoes and overboots
Overshoes are clothing protections implemented on shoes. The overboots protect the high shoes, they go up higher than the overshoes.
The applications are multiple:
Disposable overshoes and overboots
In clean environments such as hospitals or the food and pharmaceutical industries, shoes are vectors of dirt. They transmit micro-organisms. These can contaminate a room and cause illness or infect foodstuffs. To maintain a clean environment, disposable (often non-slip) overshoes or overboots can be used. These are disposable and ensure optimal hygiene.
In other cases, the footwear is protected by disposable boot covers, designed to protect footwear from light liquid splashes and hazardous dust.
Other devices
But overboots are not always for single use. They are then real protective devices.
° Motorcycle overboots to protect against rain and cold;
° Expedition overboots for ski boots and high mountain boots for protection against the cold;
° Snow overboots to protect hikers from snow and rain, mainly for the use of snowshoes;
° Bicycle overboots to protect against the cold;
° Antistatic overboots;
° Anti-slip overboots…
An example OBOOTS® from Ouvry® = CBRN protective overboots
This overboots, composed of a single piece of butyl molded by injection process, has obtained the CE marking following some requirements of the European standards EN ISO 20347:2012, EN15090:2012 §6.3.3 and EN13832-3: 2018
What do these standards mean?
– To test the general properties of a protective shoe:
EN ISO 20347:2012. Personal protective equipment, work shoes.
The overboots comply with the main requirements of a professional protective footwear such as the height of the upper, waterproofness, slip resistance on a tiled floor with SLS (Sodium Lauryl Sulfate), antistatic properties, tensile properties and flexural strength, tear resistance, sole resistance to hot contacts…
– For testing flame resistance:
EN15090:2012 §6.3.3 Firefighters’ footwear, flame resistance
EN ISO 15025:2016 Protective clothing – Protection against flame – Test method for limited flame spread
– To test the protection against chemicals
EN13832-3: 2018, with the following chemicals: sodium hydroxide 40% – nitric acid 65% – acetic acid 99%.
For all products, the protection level is equal to 5, i.e. the maximum performance level: no permeation after 1,921 min (32 hours).
This equipment is fully decontaminable, the sole clings perfectly to the ground, and is resistant to flames and chemical products.
NB: not all test results are reported here.
These overboots will be very useful when there is a risk of wading in contaminated water.
Examples: medical personnel working on CBRN decontamination lines whose feet are in contact with contaminated water, military personnel or intervention forces during risky operations walking in soiled water puddles or even industrialists in charge of decontamination and remediation, confronted in their daily life with puddles of liquid chemical products
What about socks?
In the field of CBRN, the feet of personnel wearing simple intervention shoes are not protected against CBRN agents in the form of vapor. Ouvry® has developed CBRN socks made of a filtering media based on activated carbon microbeads, permeable to air and water vapor but trapping toxic products such as HD vapors for 24 hours.
Conclusion
As we have seen recently, if it is important to protect our hands with gloves, it is also fundamental to protect our feet. In the professional environment, there are models of shoes corresponding to each risk. In some cases, it is much simpler and more advantageous to have overboots, which can be decontaminated and reused and used with any type of footwear. These PPEs also follow rigorous standards regarding comfort, resistance to walking and, as in the case of the Oboot, protection against chemicals.
To go further
https://www.inrs.fr/risques.html [1]
https://www.inrs.fr/media.html?refINRS=ED+994 [2]
https://fr.wikipedia.org/wiki/Chaussure_de_s%C3%A9curit%C3%A9 [3]
http://dictionnaire.sensagent.leparisien.fr/chaussure%20de%20s%C3%A9curit%C3%A9/fr-fr/ [4]