Safety officials now know why Takata airbags explode with too much force – an issue that has caused 12 deaths and more than 100 injuries around the world.
The faulty airbags suffer from a fault that causes them to explode more violently during a crash than they should, which lead to an initial recall of 28.8 million inflators, making it the biggest consumer recall in US history.
Takata has since said it is recalling another 35 to 40 million inflators, taking the total to 63.8 million cars affected in the US – more than a quarter of all vehicles on US roads.
The National Highway Traffic Safety Administration (NHTSA) enlisted the help of former industry chemist and propellant expert H.R. Blomquist to evaluate the work of three ongoing investigations looking into the long-running Takata airbag issue.
In his report, Blomquist blames the faulty inflator design, which he says lets humid air slowly trickle into the inflator. This allows moisture to meet a moisture-sensitive propellant that slowly degrades over time due to fluctuations in temperature.
When a crash happens, Blomquist explained, “the damaged propellant burns more rapidly than intended, and over pressurises the inflator’s steel housing causing fragmentation”. These fragments become a form of shrapnel that can harm the driver and passengers.
The degradation can happen within as little as six years, the report noted. Owing to the temperature fluctuation aspect, it is more of an issue in older cars that are driven in hot and humid clients such as Malaysia, where the two most recent deaths occurred.
Not all Takata airbags have been affected. Those that use the problematic ammonium nitrate but feature desiccant, a substance that is used to help absorb moisture, are not part of the latest recall.
Other airbag manufacturers started using guanidine nitrate instead of ammonium nitrate because of the safety concerns.
The Japanese company is said to be cooperating in the recent probes, but NHTSA administrator Mark Rosekind said it had originally, “misled, obscured and withheld information from the NHTSA, consumers and their customers in the automotive industry”.
After the death of a 17-year-old girl near Houston, Texas, Rosekind told reporters: “Please, as you report your stories, include this. Vehicle owners who have received notice that there are parts available for their repair should take action immediately.”
Creating a safe replacement part is being worked on as quickly as possible, but Rosekind said it has to hold back somewhat to avoid running the risk of introducing a new inflator that’s just as dangerous.
The NHTSA has urged owners of a car with a faulty Takata airbag to use another car, which is wise advice when it will take years to fix the sheer number of vehicles affected.
Stock in Takata dropped 9.25 per cent after the extended recall was announced. Of all the car manufacturers, Honda has been most affected.
Given the number of deaths and injuries and the fact that more than a quarter of all cars in the US could be a ticking time bomb, it seems a greater level of action is needed.