Northern Health says there's been an increase in overdose events in Terrace due to a reported substance being sold as down.

The health authority describes the substance as purple, blue and chalky.

It says it is highly toxic, causes heavy and prolonged sedation, and requires more naloxone to reverse.

The overdoses are happening when the substance is smoked and injected.

For safety, the health authority recommends carrying naloxone, getting overdose prevention training, not using alone and using the overdose prevention site in Terrace.

B.C. Emergency Health Services says 259 overdose calls were made in Terrace in 2021. That number has been increasing steadily year by year -- 59 were reported in 2018, 98 in 2019 and 208 in 2020.