The research highlights that this material, which is also a major waste product of the paper industry, could be a natural alternative to the synthetic compounds that dominate the category.
Currently the most commonly used UV ingredient is nano titanium oxide, but concerns over potential toxicity and allergies in some users means the search continues for alternatives.
This has triggered the search for natural-based alternatives for sunscreen formulations, with an emphasis on all-important efficacy as well as safety.
The search for natural sunscreen boosters
To date natural alternatives that have proved to be sunscreen formulation boosters have included green coffee, soy and papaya, but now the spotlight falls on lignin, which carries the additional benefit of being a byproduct that would otherwise be discarded.
The research has been backed by the American Chemical Society and the findings on what types of lignin are best suited for the job were published in the journal ACS Sustainable Chemistry & Engineering.
The researchers, which included Shiping Zhu, Xueqing Qiu and colleagues focused their lab work on five types of lignin to see which enhanced the Sun Protection Factor (SPF) of sunblock the most.
The type of lignin matters
The type of lignin that showed the most improvement in the sunscreen efficacy is called organosolv, and the researchers state in the journal article that just 1% of this compound helped to double the lotion's original SPF, boosting it from 15 to 30.
Likewise, the researchers also tested a lotion containing 10% organosolv, demonstrating that a standard SPF 15 formulation was boosted to give an SPF of 92.
However, the researchers also reported that the larger dosing meant excessive amounts of hydrophilic lignin such as lignosulfonate caused the product to start separating.
Although the research team states that more research has to be conducted to establish both the safety and efficacy of lignin, the results so far have proved to be encouraging and look to be the first step towards the development of sunscreen containing the compound.