Amazon warehouse workers in New York are pushing for unionization to fight what they claim are unfair quotas and insufficient breaks.

Staff at Amazon's new warehouse in Staten Island officially announced their campaign in December, backed by the Retail, Wholesale and Department Store Union.

They have raised safety and health concerns regarding 12-hour shifts and demands they pack 240 to 400 items per hour; one every 10-15 seconds.

Demonstrators shout slogans and hold placards during a protest at the Amazon fulfillment center in Shakopee, Minnesota last month

'They overwork you and you're like a number to them,' an employee at Amazon's Staten Island warehouse told The Guardian.

'In July, I had Prime week and worked 60 hours. The same day I worked overtime, I got into a bad car accident because I was falling asleep behind the wheel.'

Another employee added said: 'Right now, at that fulfillment center [in Staten Island], if an employee is a picker, they want that person to pick up 400 items per hour, picking each item every seven seconds.'

Amazon has more than 75 'fulfillment centers' across the U.S. where purchased merchandise is packaged and shipped.

The centers employ more than 125,000 full-time employees, according to Amazon.

A group of Amazon workers in Minnesota demand better working conditions during a protest outside one of the retailer's warehouses

The retail giant has faced past complaints from warehouse employees about working conditions, with protests held in Europe as well as the U.S.

Last month, the Seattle-based retail giant announced plans to build part of its second headquarters in Long Island City in Queens which will employ 25,000 people.

This sparked protests with hundreds of locals taking to the streets to condemn the nearly $3 billion in tax breaks and cash grants for the company, expressing worry that the move will drive up rents and overload public transit.

In a statement released in December, Amazon said: 'We work hard every day to ensure all of our employees are treated fairly and with dignity and respect.

'Amazon offers a great employment opportunity with excellent pay – ranging here from $16.25-$20.80 an hour, and comprehensive benefits including health care, up to 20 weeks parental leave, paid education, promotional opportunities, and more.