Mount Maunganui based company Road Science has created award-winning innovative work in eliminating health hazards in roading products.

The transport technology company was the winner of the WorkSafe New Zealand Best initiative to address a work-related health risk at the New Zealand Workplace Health and Safety Awards.

Its innovative work involved eliminating the risk of hydrogen sulphide being emitted when manufacturing and storing bituminous products.

While H2S is a hazardous gas that naturally forms in crude oil and bitumen, it can occur in potentially fatal concentrations when mixed with other chemicals to develop polymer modified bitumen roading products.


Therefore, the team set out to develop a system which reduces this risk significantly, to help prevent any health and safety incidents.

Nik Vishwanath accepting the award. Photo / Supplied
Nik Vishwanath accepting the award. Photo / Supplied

Road Science ended up eliminating the risk completely and is adopting the new system as standard practice in its manufacturing plants, with a goal for this to be standard practice in all plants around New Zealand.

General manager Murray Robertson said the award was fantastic recognition for the dedication and hard work of Nik Vishwanath, Darcy Rogers and the wider Road Science business.

"We challenged the team to not just mitigate the risk, but instead remove it completely, and it was really pleasing to see the teams work collaboratively to achieve a superb outcome."

Process engineer Nik Vishwanath said to improve the stability and performance of a polymer modified bitumen product, sulphur is often added to create a cross-link.

"This is a bond between the different polymer chains and the bitumen, ensuring the two entities work to hold the road together, therefore improving the product's lifespan and eliminating the need for frequent road repairs."

While adding sulphur is common practice in creating polymer modified bitumen products, a byproduct of this is an increase in H2S.

As such, Road Science sought to improve the health and safety of its workplace by reviewing their current control processes for H2S.

Through conversations with their suppliers and research in their laboratory, the Road Science team developed a chemical substance, called a "scavenger", that would react with the H2S and turn it into an inert, non-hazardous compound - zinc salt.

"After lab tests and small scale trials showed positive results, we created a system which added the scavenger to our current PMB products," Vishwanath said.

"We then measured the H2S levels in our tank vents and the manholes of our trailers, where the concentrations had been the highest.

"Within half an hour, the H2S levels were down to zero."