Airbag

Subject – Science and Tech

Context – Six airbags could be mandatory in your car soon

Concept –

An airbag is a vehicle occupant-restraint system using a bag designed to inflate extremely quickly, and then quickly deflate during a collision.
It consists of the airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor.
The purpose of the airbag is to provide a vehicle occupant with a soft cushioning and restraint during a collision. It can reduce injuries between the flailing occupant and the interior of the vehicle.
On 5 March 2021, the Indian Ministry of Road Transport and Highways mandated that all new vehicle models introduced in India after 1 April 2021 have dual front airbags; the regulation also requires that all existing models be equipped with dual front airbags by 31 August 2021.

How do air bags work?

The chemical at the heart of the air bag reaction is called sodium azide, or NaN3.
Under normal circumstances, this molecule is quite stable. If heated, though, it will fall apart.
The chemical equation 2 NaN₃–> 2 Na + 3 N₂ describes exactly how it falls apart.
- A handful (130 grams) of sodium azide will produce 67 liters of nitrogen gas–which is enough to inflate a normal air bag.
- Sodium is a very reactive metal that will react rapidly with water to form sodium hydroxide; as a result, it would be quite harmful if it got into your eyes, nose or mouth. So to minimize the danger of exposure, air bag manufacturers mix the sodium azide with other chemicals that will react with the sodium and, in turn, make less toxic compounds.
There are sensors in the front of the automobile that detect a collision. These sensors send an electric signal to the canister that contains the sodium azide and the electric signal detonates a small amount of an igniter compound. The heat from this ignition starts the decomposition of the sodium azide and the generation of nitrogen gas to fill the air bag.
From the time the sensor detects the collision to the time the air bag is fully inflated is only 30 milliseconds, or 0.03 second.

What is an ‘M1’ vehicle?

Under the government’s homologation rules, vehicles are bucketed into broad categories. ‘Category M’ covers motor vehicles with at least four wheels, used for carrying passengers.
And the sub-category ‘M1’ defines “a motor vehicle used for the carriage of passengers, comprising not more than eight seats in addition to the driver’s seat”.

What is homologation?

Homologation is the process of certifying that a particular vehicle is roadworthy, and matches certain specified criteria laid down by the government for all vehicles that are built or imported into the country.
Tests are carried out to ensure that the vehicle matches the requirements of the Indian market in terms of emissions, and safety and roadworthiness, as laid down by the Central Motor Vehicle Rules.

The Supreme Court Committee on Road Safety

It was headed by former apex court judge Justice K S P Radhakrishnan(later by retired judges, Justice A M Sapre)

Brasilia Declaration on Road Safety

The declaration was signed at the Second Global High-Level conference on Road Safety held in Brazil.
Through the Brasilia Declaration Countries plan to achieve the Sustainable Development Goal 3.6: By 2020, halve the number of global deaths and injuries from road traffic accidents.
United Nations has also declared 2010-2020 as the decade of action for Road Safety.
Countries should form transport policies in order to favor more sustainable modes of transport such as walking, cycling and using public transport.