Canterbury farmers are being warned to take extreme care around their silos in case of damage.

69 silos have failed since the quake last Saturday, but it’s thought that number will top 100.

Federated Farmers Mid-Canterbury Grain & Seed Chairperson David Clark says any farmers suspecting their silos may have been damaged should call an engineer or their supplier.

“It would be irresponsible of Feds to issue blanket advice as to how to empty these silos.

"Each of these need an individual visit to look at the damage to each silo, and the people who are best qualified to assess that are the companies that supplied them and the engineers who work for them."

Mr Clark says reports of some of the methods used to empty damaged silos are worrying.

"I guess it’s also timely to remind farmers that the rules around [Occupational Safety and Health] still apply. There’s some strict regulations there, and even an earthquake is no excuse.

"The legislation would be pretty severe if there was an accident, and we wouldn’t want a tragedy to overshadow this, it’s bad enough already.”