The 3 ½-year sentence handed out today in the deaths of four Toronto construction workers marks the first time in Ontario that someone has been handed jail time under a 2004 law that makes employers criminally liable for workplace safety lapses.

Vadim Kazenelson was the project manager for six workers repairing balconies on the 13th floor of a Kipling Avenue apartment building on Christmas Eve 2009. Only one man was wearing a safety harness when the swing-stage they were working on collapsed. Four men died and one was seriously injured when they plummeted more than 30 metres.

Kazenelson was sentenced on four counts of criminal negligence causing death and one count of criminal negligence causing bodily harm under the "Westray Law," a change to the Criminal Code that imposed stiff penalties for workplace health and safety violations that kill or injure workers.

"A significant term of imprisonment is necessary to reflect the terrible consequences of the offences," said Justice Ian MacDonnell in handing down the 3 ½-year term.

Despite the sentence, Kazenelson is not headed immediately to prison. He is appealing his conviction and has been granted bail pending that appeal.

Only a handful of others across the country have been convicted of criminal negligence connected to the workplace since the law was changed, including:

A BC Ferries navigation officer was sentenced to four years in prison on June 24, 2013, after being convicted of criminal negligence causing death. Karl Lilgert got distracted and didn't notice that the Queen of the North ferry had gone off course. The vessel then ran aground and two passengers died as the ferry sank in March 2006. Lilgert tried to appeal his sentence, but the Supreme Court of Canada refused to hear his appeal in May.

A Quebec landscape contractor was convicted of criminal negligence causing death in September 2010, after one of his employees was crushed to death by a backhoe the contractor had been driving. An investigation found that the 30-year-old backhoe had not received regular maintenance since the contractor bought it, nor had it undergone a formal inspection in five years, the Canadian Centre for Occupational Health and Safety reports. The Quebec man received a two-year conditional sentence.

The 2004 changes to the law also led to a harsher penalty for Metron Construction Inc., the firm who employed Kazenelson and the other workers.

A judge initially fined the company $200,000 in July 2012 after it pleaded guilty to criminal negligence causing death, as well as $142,500 in victim and other surcharges.

But the Ontario Appeal Court overturned that sentencing decision in September 2013, saying that the lower fine reflected guidelines from the Ontario Health and Safety Act — and not the new sentences outlined in the Criminal Code.