Skin protection not always good for auto materials

Sanitizers, sunscreen, insect repellent can prematurely age auto materials

Published: June 15, 2019, 10:30 PM
Updated: June 19, 2019, 11:35 PM

sunscreen application

They provide some of the best protection we can offer our skin, but they’re also some of the most harmful compounds for your vehicle — hand sanitizer, sunscreen and insect repellent.

touch surfaces

“From hand sanitizers to sun lotions to insect repellent, consumer trends are constantly changing, and new products are coming on to the market all the time,” said Mark Montgomery, senior materials engineer at Ford of Europe’s Materials Technology Centre in the UK. “Even the most innocuous seeming product can cause problems when they come into contact with surfaces hundreds and even thousands of times a year.”

The chemicals in said products offer quick and convenient protection against germs or harmful solar radiation but can prematurely age plastics, paint and other materials in our vehicles. Hand sanitizer usually contains alcohol in a concentration of about 65%. That concentration will dry out your skin, which is why the compound often includes skin softeners, and will do the same to plastic touch surfaces, such as steering wheels, door pulls and shift knobs and brake handles.

The problem is exacerbated with sanitizers with higher concentrations, which can be found as high as 95%. The higher the percentage, the more rapidly it is to dry a surface it comes in contact with.

“Sometimes what we do requires a bit of detective work,” said Richard Kyle, Ford of Europe materials engineer. “There were instances of particularly high wear in Turkey and we managed to trace it back to ethanol potentially being a contributing factor, and most likely a popular hand sanitizer that contained 80% ethanol – far higher than anything we’d seen before.”

touch surfaces

Similarly, sunscreen contains one or a mixture of some three dozen chemicals designed to either reflect harmful ultraviolet (UV) light or absorb it. One of the most common is titanium oxide, which can react with plastics and the natural oils in leathers. The effect is most notable on hot surfaces.

Insect repellents, on the other hand contain DEET, which is not friendly with many insects but also doesn’t like painted surfaces because it is an effective solvent. It can dissolve synthetic fabrics such as rayon and spandex, watch crystals and painted/varnished surfaces, and it can be absorbed by hard plastics, softening them.

touch surfaces

Ford’s materials engineers test new vehicle materials at temperatures up to 74 Celsius, or accelerate bombardment by UV light to check longevity of years in a matter of days. They also test the strength of plastics at both extremes of the temperature range.

The teams then use the findings to develop the constitution of protective coatings to apply to surfaces that may come in contact with protected human skin to ensure increased resiliency and longevity for in-vehicle materials.