EPA: Stay safe mixing chemicals

Dr Fiona Thomson-Carter

The Environmental Protection Authority has released new guidance to highlight the dangers around mixing products containing hazardous substances — whether at work, on your land, at home, or anywhere else.

"It's important to understand the implications of mixing chemicals," says Dr Fiona Thomson-Carter, general manager of the EPA's Hazardous Substances Group.

"Mixing the wrong things together can pose a risk to people and the environment.

"While commercial manufacturers have experienced and competent staff, we believe the practice of creating 'tank mixes' is commonplace in backyards across the country: you may be creating and spraying these at work, on your farm, lifestyle block or section, or in an urban garden.

Mixing the wrong things together can pose a risk to people and the environment.

Dr Fiona Thomson-Carter

"We know that most people create them according to the instructions, but we are equally aware of others who create their own.

"If you think back to basic chemistry when your chemistry teacher explained how mixing different chemical substances can cause a reaction, the result can be just the same," says Dr Thomson-Carter.

"If you mix random products together, it's anyone's guess as to how those chemicals will behave."

Some products are designed to be mixed.

Others may need to be combined in a particular way, and there can be unexpected consequences: substances may become unstable, toxic to people and the environment, and sometimes not as effective, she says.

"We encourage everyone to read our new web guidance to better understand the risks and ensure they stay safe," says Dr Thomson-Carter.

Read the guidance available on the EPA's website https://www.epa.govt.nz/