Basic Guide to the National Labor Relations Act

Subparagraph (B)—Prohibited object: Compelling recognition of an uncertified union. Section 8(b)(4)(B) 
contains the Act’s secondary boycott provision. A secondary boycott occurs if a union has a dispute with Company 
A and, in furtherance of that dispute, causes the employees of Company B to stop handling the products of Company 
A, or otherwise forces Company B to stop doing business with Company A. The dispute is with Company A, called 
the “primary” employer, the union’s action is against Company B, called the “secondary” employer, hence the term 
“secondary boycott.” In many cases the secondary employer is a customer or supplier of the primary employer with 

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whom the union has the dispute. In general, the Act prohibits both the secondary boycott and the threat of it. 
Examples of prohibited secondary boycotts are: 
Examples of violations of Section 8(b)(4)(B). 
•
Picketing an employer to force it to stop doing business with another employer who has refused to 
recognize the union. 
•
Asking the employees of a plumbing contractor not to work on connecting up airconditioning equipment 
manufactured by a nonunion employer whom the union is attempting to organize. 
•
Urging employees of a building contractor not to install doors that were made by a manufacturer that is 
nonunion or that employs members of a rival union. 
•
Telling an employer that its plant will be picketed if that employer continues to do business with an 
employer the union has designated as “unfair.” 
The prohibitions of Section 8(b)(4)(B) do not protect a secondary employer from the incidental effects of union 
action that is taken directly against the primary employer. Thus, it is lawful for a union to urge employees of a 
secondary supplier at the primary employer’s plant not to cross a picket line there. Section 8(b)(4)(B) also does not 
proscribe union action to prevent an employer from contracting out work customarily performed by its employees, 
even though an incidental effect of such conduct might be to compel that employer to cease doing business with the 
subcontractor. 
When an employer is not protected from secondary strikes and boycotts. In order to be protected against the 
union action that is prohibited under this subparagraph, the secondary employer has to be a neutral as concerns the 
dispute between the union and the primary employer. For secondary boycott purposes an employer is considered an 
“ally” of the primary employer and, therefore, not protected from union action in certain situations. One is based on 
the ownership and operational relationship between the primary and secondary employers. Here, a number of factors 
are considered, particularly the following: Are the primary and secondary employers owned and controlled by the 
same person or persons? Are they engaged in “closely integrated operations?” May they be treated as a single 
employer under the Act? Another test of the “ally” relationship is based on the conduct of the secondary employer. 
If an employer, despite its claim of neutrality in the dispute, acts in a way that indicates that it has abandoned its 
“neutral” position, the employer opens itself up to primary action by the union. An example of this would be an 
employer who, claiming to be a neutral, enters into an arrangement with a struck employer whereby it accepts and 
performs farmed. out work of that employer who would normally do the work itself, but who cannot perform the 
work because its plant is closed by a strike. 
When a union may picket an employer who shares a site with another employer. When employees of a primary 
employer and those of a secondary employer work on the same premises, a special situation is involved and the 
usual rules do not apply. A typical example of the shared site or “common situs” situation is when a subcontractor 
with whom a union has a dispute is engaged at work on a construction site alongside other subcontractors with 
whom the union has no dispute. Picketing at a common situs is permissible if directed solely against the primary 
employer. But it is prohibited if directed against secondary employers regularly engaged at that site. To assist in 
determining whether picketing at a common situs is restricted to the primary employer and therefore permissible, or 
directed at a secondary employer and therefore violative of the statute, the NLRB and the courts have suggested 
various guidelines for evaluating the object of the picketing, including the following. 
Subject to the qualification noted below, the picketing would appear to be primary picketing if the picketing is: 
1. Limited to times when the employees of the primary employer are working on the premises. 
2. Limited to times when the primary employer is carrying on its normal business there. 
3. Confined to places reasonably close to where the employees of the primary employer are working. 
4. Conducted so that the picket signs, the banners, and the conduct of the pickets indicate clearly that the dispute 
is with the primary employer and not with the secondary employer. 
These guidelines are known as the Moore Dry Dock standards from the case in which they were first formulated 
by the NLRB. However, the NLRB has held that picketing at a common situs may be unlawful notwithstanding 
compliance with the Moore Dry Dock standards if a union’s statements or actions otherwise indicate that the 
picketing has an unlawful objective.