SAFETY ALERT: Red-label Masters Metallic Compound

Many contractors within the gas distribution sector have traditionally used a thread and gasket sealant with the tradename: Masters Metallic Compound (“MMC”) with a red identifying label.  Recently a leading gas distribution utility company directed our industry to cease the use of MMC due to its high lead content and directed a switch to the use a lead-free alternate product.

The MMC product has been classified as hazardous under Canadian WHMIS regulations (Hazardous Products Regulations) (WHMIS 2015).  When working with threaded connections on previously installed gas distribution systems, please ensure all installers follow the special handling procedures outlined on the MMC safety data sheet, which can be found at: (

On a go-forward basis, switching from the lead-containing MMC to lead-free products is a prudent step and must be complemented with proper safety procedures including use of personal protective equipment.

Any installers who have concern regarding their actual (or potential) prior exposure to the MMC product are advised to review with their employer’s safety leadership team to receive information on how to address their individual concerns.

Health and safety of everyone working in our industry is of paramount importance.  Please ensure that your team is fully aware of this notice.

Find official release here.

Safety Alert Issue Date: March 6, 2020