How Labor Scabs Work

By: Dave Roos
Strikers fight with a group of scabs as they try to cross a factory picket line in this photo from 1935. See more corporation pictures.
American Stock/Getty Images

There are few people who inspire as much controversy as the labor scab -- a union worker who returns to the job without permission from the union, or a nonunion employee who needs the work and is willing to put up with taunts, threats and even violence from strikers. In either case, he or she is the mortal enemy of the labor union, an organization that's designed to protect the interests of workers from the possible tyranny of management. The only true weapon of the labor union is a strike, and scab labor renders a strike useless. For employers who want to break the unions, one of their greatest weapons is the scab.

The term "scab" was first used in the 13th century to mean a nasty, itchy skin disease or the crust that forms on a wound. By 1806, the word "scab" arrived at its current meaning -- a strikebreaker who willingly crosses the picket line [source: Lexicon of Labor, Online Etymology Dictionary]. In England, scabs are also called "blacklegs."


Keep reading to better understand the relationship between unions and scabs, to hear about some of the most famous scab conflicts and to find out if there's actually a positive side to scab labor.

Unions, Strikes and Scabs

Teamsters yell at scabs as they drive across the picket line during a strike.
John Mottern/AFP/Getty Images

In the late 19th and early 20th centuries, industrial workers around the world reached a breaking point. Frustrated with dangerous labor conditions, low pay and zero job security, they came together to form the first labor unions. Whereas the complaints of one, two or 10 workers could be easily ignored by management, the united voice of thousands of workers demanded attention.

Labor unions are founded on the principle of collective bargaining. Collective bargaining consists of negotiations between an employer and a group of employees, usually represented by a union. When it works, collective bargaining is good for both the worker and the employer. The worker gets a better salary, reasonable schedules and health benefits, and the employer is relieved of the burden of negotiating individually with each and every worker. But when collective bargaining doesn't work, you get a strike.


Scab labor has the potential to completely undermine the power of a labor union. The key to a successful strike is that every union member participates. If half of the employees stay behind -- or are replaced by nonunion workers -- management can still keep the factory running and wait until the striking workers are desperate enough to accept its conditions. When scabs fill jobs, the striking worker has two options -- either return to work under the same old conditions or look for a new job.

Scabs, also known as replacement workers, are legal in most parts of the world. In the U.S., the National Labor Relations Act (NLRA) of 1935 establishes strict protections for unions, but allows employers to permanently replace striking workers if the strike is based on economic gain [source: Legal Dictionary]. In a recent case, a 7th Circuit Court ruled that an employer can even refuse to hire back striking workers if their jobs are occupied by permanent replacements, further undercutting the power of strike actions [source: U.S. Court of Appeals]. In the Canadian provinces of British Columbia and Quebec, however, it's illegal under any circumstances to hire scabs [source: Canadian Labour Congress].

Over the past two centuries, scabs have played pivotal roles in some of the world's most famous and most violent labor strikes. Read more about them in the next section.


Famous Strikes

In 1892, there was a series of famous strikes in the United States -- a general strike in New Orleans, a copper miners' strike in Idaho and a coal miners' strike in Tennessee -- but none became as famous as the Homestead Strike against Andrew Carnegie's steel empire in Pennsylvania [source: PBS].

Carnegie's plant manager, Henry Frick, wanted to break the steel workers' union by slashing wages, provoking a strike and bringing in scab labor. Things didn't go quite as planned. Not only did the workers go on strike, but they physically occupied the steel plant, shielding it from scab workers. Frick called in hired guns called Pinkerton detectives to crush the rebellion.


On the night of July 5, 1892, barges carrying hundreds of armed Pinkerton detectives floated up the river toward the Homestead plant. The Pinkertons were met with violent resistance. By the end of the 14-hour gunfight, three detectives and nine workers were dead [source: PBS]. Frick called in military support from the governor and trucked in scab labor. The steel worker's union eventually gave in to Frick's demands, which sapped the power from steel unions for decades.

Andrew Carnegie never recovered from the tragic events at Homestead, saying later, "…but the false step was made in trying to run the Homestead Works with new men. It is a test to which workingmen should not be subjected. It is expecting too much of poor men to stand by and see their work taken by others."

Some of the largest and longest strikes in history were eventually undermined by scab labor. In the early 1890s, several of Australia's major unions, including those representing miners, maritime laborers and wool shearers, went on strike for higher wages, fairer treatment and the right to organize [source: Armstrong].

The bosses brought in scab labor -- which was plentiful due to widespread unemployment -- and there were many violent clashes between striking workers and their replacements. The maritime strike broke under the weight of the scab labor, and the shearers' strike escalated to armed confrontations and dragged on for years before finally failing as well.

The Herrin Massacre is one of history's most notorious scab labor tragedies. On June 22, 1922, in the town of Herrin, Ill., striking coal miners surrounded a mine full of nonunion scabs. Armed with rifles and farm implements, the strikers promised that if the scabs surrendered, they would be escorted safely out of town. Instead, the scabs were marched through Herrin and into the woods, where 20 of them were murdered and others seriously injured [source: Encyclopedia Britannica]. A jury acquitted all the strikers of wrongdoing.

In the next two sections, we'll look at the negatives and also the positives of scab labor.


Arguments Against Scab Labor

Arguments against scab labor continue to this day. As we mentioned earlier, the existence of scab labor is a constant threat to the viability of collective bargaining. Unfortunately for unions, the popularity of permanent replacement workers has been on the rise for years. There are large staffing companies throughout the U.S. that specialize providing emergency labor during strikes, and the courts have increasingly sided with employers in cases where striking laborers return to work to find that their jobs have been permanently filled by scabs.

Prior to 1981, no major U.S. industry had hired permanent replacements during a strike, even though the law allowed them to do so [source: Schlach]. The turning point came with the federal air traffic controllers' strike [source: Kilborn]. When 11,500 air traffic controllers walked off the job in 1981, President Ronald Reagan declared the strike illegal and called for all striking workers to be fired and permanently replaced with scabs. Reagan's decision was a huge blow to the power of unions. In the decades leading up to the air traffic controllers' strike, there was an average of 300 major labor strikes a year in the U.S. By 2006, the average had dropped to less than 30 a year [source: Schlach]. The lesson: Scabs make strikes ineffective.


Another negative side of scab labor -- for unions, employers and consumers -- is that some replacement workers have been accused of producing lower quality, even dangerous products. The most high-profile case is the Bridgestone-Firestone tire recall of the late 1990s. According to an independent study, a significant number of tires produced by replacement workers at the Firestone plan in Decatur, Ill. in 1994 and 1995 were defective and had potentially deadly tread separations. One out of every 400 tires manufactured in Decatur during the strike was returned by 2000 [source: Krueger].

Due to the deep resentment that some strikers have toward scabs, people who cross picket lines may face great danger. Nearly every major labor strike of the19th and early 20th century includes tales of injury, torture and even the death of scabs at the hands of striking workers.

A New York Times article from 1910 describes conditions during a plumbers' strike in Paris. Strikebreakers were detained by union officials who beat them, robbed them and forced them to join the union [source: The New York Times]. During the British miners' strike of the early 1980s, violent clashes between miners and police escalated when buses of scabs were brought in to replace them. Public opinion turned against the union when two striking miners dropped a 45-pound (20.4-kilogram) cement block onto the car of a scab, killing the driver [source: BBC]. Recently, a scab truck driver in Spain was badly burned when strikers set his vehicle on fire [source: Mail Online].

Some striking teachers and nurses have threatened and intimidated colleagues who cross the picket line. In 2007, a striking teacher was forced to shut down a Web site where he posted photos of teachers who crossed the picket line, implying that strikebreakers would pay for their actions [source: Noceda].

Despite the arguments against scab labor, some experts claim that scabs can also serve a positive purpose. Read more in the next section.


Replacing Union Workers

A truck driven by a replacement worker moves Coca-Cola soft drinks to market during a 2005 strike in California.
David McNew/Getty Images

A successful relationship between union laborers and employers relies on a delicate balance of power. Some employers view the right to hire scab labor as a way to maintain that balance. They say that scabs are necessary bargaining chips at the negotiation table to combat unfair union demands.

This argument is hard to swallow for many union workers, but there's a certain logic to it, particularly in the case of smaller businesses [source: Lemay]. Imagine a factory in rural Michigan. Economic times are tough and the factory is barely making a profit. The union, upset that wages haven't increased in years, calls for a strike. Now the company is in an even tougher economic situation. With production at a standstill, it's losing hundreds of thousands of dollars a day, and the only way to get employees back to work is by meeting their demands.


By temporarily replacing union workers, the small company can generate some revenue while negotiations with the union continue. Some of the factory's economic pressure has been lifted, allowing both sides to approach the negotiating table on equal terms.

It can also be argued that the existence of scab labor may actually be a protection for union workers. Let's say that it was suddenly illegal to hire replacement workers -- legislation that's been proposed in U.S. and Canada for years. If you were running that factory in Michigan, you would do everything in your power to limit your exposure to labor unions [source: Lemay]. The more union workers you hire, the greater your risk if they go on strike. And without the option to hire replacement workers, you'll have to bow to the union's demands, even if you feel they're excessive.

Another argument for replacement workers is what's called the "market test theory" which is based on the principles of supply and demand [source: Ferrara]. Here's how it works: U.S. law permits a company to hire permanent replacement workers only in the case of an economic strike or a strike over wages -- not one based on workers seeking greater benefits or alleging unfair treatment. If a union calls a strike asking for a fair wage increase, then the employer will have a hard time finding replacement workers who will work for a below-market salary. However, if the union asks for an excessive or above-market wage increase, then the employer will easily find replacement workers willing to accept the lower but reasonable market price.

The market test theory argues that without the ability to hire permanent replacement labor, unions will exercise a monopoly that raises wages so far beyond fair market value that employers will no longer be able to do business [source: Ferrara].

As we've seen, quite a bit of controversy and risk of physical danger surrounds labor scabs. For lots more information on scabs, strikes and unions, follow the links on the next page.


Lots More Information

Related HowStuffWorks Articles

More Great Links


  • Lexicon of Labor. "Scab." New Press. 1998
  • Online Etymology Dictionary. "Scab"
  • Farlex. The Free Dictionary. Legal Dictionary. "Unfair Labor Practice"
  • Canadian Labour Congress. "Anti-Scab Legislation: the Case for Balance and Fairness." December 5, 2006.
  • PBS American Experience. "Andrew Carnegie: the Homestead Strike"
  • Armstrong, Mick. Socialist Alternative. "Aust Radical History: The Great Strikes." April-May, 2007
  • Encyclopædia Britannica Online. "Herrin." October 17, 2008
  • Diaz, Richard. The Love of Sports. "Scab Ball." May 18, 2008
  • The Baseball Almanac. "Replacement Players in the Major Leagues"
  • Kilborn, Peter T. The New York Times. "Replacement Workers: Management's Big Gun." March 13, 1990.
  • Schlach, Kathleen. National Public Radio. "1981 Strike Leaves Legacy for American Workers." August 3, 2006
  • Krueger, Alan B.; Mas, Alexandre. National Bureau of Economic Research. "Strikes, Scabs And Tread Separations: Labor Strife And The Production Of Defective Bridgestone/Firestone Tires." February, 2003.
  • The New York Times. "Paris Plumbers on Strike." September 18, 1910.
  • BBC. "Wales History: The Miners' Strike"
  • Mail Online. "'Scab' driver burned in his lorry as European protests against high fuel prices turn violent." June 13, 2008
  • Lemay, Guy; Kozhaya, Norma. National Post. "Workers Pay for Anti-Scab Laws." January 8, 2005
  • Noceda, Kristopher. Oakland Tribune. "Forget sticks and stones: Teachers aim at 'scabs.'" April 12, 2007