## Facts

- Mastro Plastics Corporation and French-American Reeds Manufacturing Co. operated manufacturing facilities in Brooklyn, New York.
- Employees were covered by a one-year collective bargaining agreement (CBA) with Local 3127 of the United Brotherhood of Carpenters and Joiners, expiring November 30, 1950.
- The CBA contained a no-strike clause stating the union would “refrain from engaging in any strike or work stoppage during the term of this agreement.”
- A rival union (Local 65) campaigned to represent the employees; Mastro viewed the incumbent union as weak and sought to replace it with another local (Local 318).
- Mastro supported and induced employees to join Local 318, conduct the NLRB later found was intended to oust the employees’ chosen bargaining representative.
- In October 1950, the Carpenters gave written notice of a desire to modify the CBA, triggering NLRA § 8(d)(4)’s 60-day waiting period during which strikes or lockouts over termination or modification were restricted.
- In November 1950, Mastro discharged employee Frank Ciccone, a supporter of the Carpenters and opponent of Local 318.
- The Carpenters called a strike that shut down the plant for weeks; the NLRB found the strike was solely to protest Mastro’s unfair labor practices, not to terminate or modify the CBA.
- Mastro refused to reinstate Ciccone and other strikers; the NLRB ordered reinstatement with back pay, and the Second Circuit enforced the order.

## Issues

1. Whether a broadly worded no-strike clause covering “any strike or work stoppage” waived employees’ right to strike solely in protest of employer unfair labor practices.
2. Whether NLRA § 8(d)(4)’s 60-day waiting period and loss-of-status provision stripped employees of statutory protection when they struck within that period solely to protest unfair labor practices rather than to terminate or modify the CBA.

## Decision

- The Supreme Court affirmed enforcement of the NLRB’s order.
- The Court held the no-strike clause did not waive the right to strike solely to protest unfair labor practices absent clear and explicit waiver language.
- The Court held § 8(d)(4)’s loss-of-status provision applies to strikes over contract termination/modification bargaining subjects, not to strikes solely protesting unfair labor practices.
- The strikers remained “employees” under the NLRA and were entitled to reinstatement and back pay based on the Board’s findings.

## Legal Principles

- A general no-strike clause will not be construed to waive the right to engage in an unfair labor practice strike unless the waiver is clear and explicit.
- NLRA § 13 supports a narrow construction of contractual waivers of the statutory right to strike.
- NLRA § 8(d)(4)’s 60-day waiting-period restrictions and related loss-of-status consequences are directed at economic pressure over negotiation subjects tied to contract termination or modification, not employer misconduct that violates employees’ core statutory rights.
- When the factfinder determines a strike’s sole purpose is to protest employer unfair labor practices, the strike remains protected and participating workers retain statutory employee status.

## Conclusion

The Court held that neither a broad no-strike clause nor § 8(d)(4)’s 60-day waiting-period scheme removes NLRA protection from a strike called solely to protest employer unfair labor practices, and it upheld reinstatement and back-pay remedies for the discharged striker and other participants.


Mastro Plastics Corp. v. NLRB, 350 U.S. 270 (1956)