My customer wants to know if the zinc I use meets EN 1179. What is this?

EN 1179 Zinc and Zinc alloys Primary Zinc, is a standard published by the European Committee for Standardization or CEN. The standard …specifies the classification, chemical composition, marking and other requirements for primary zinc. It has been adopted by other European standardization organizations such as British Standards (BSI). While North American galvanizers may be unfamiliar with this standard because of its infrequent use in the region, they will be familiar with ASTM B6 Standard Specification for Zinc. Both standards cover the requirements for zinc that may be used in the galvanizing process but do not cover secondary zinc produced through remelting. Each standard contains five grades of primary zinc (prime western, special high grade, etc.). Each grade has a corresponding color code that relates strongly to the two standards.

Once we know what is covered in EN 1179, the new question becomes: If the zinc I use meets one of the classifications in ASTM B6, does it also meet EN 1179? The two standards are nearly identical, however, there are a few subtle differences in chemical composition requirements between the two standards. The chart below shows which zinc grade in EN 1179 corresponds to which zinc grade in ASTM B6. It also summarizes the varying requirements of the two grades in the final column.

So does zinc that meets the requirements of one of these standards meet the corresponding grade of the other standard? The answer is: most likely. However, it will take a little bit of digging through both tables (shown below) and a look at the summarizing chart to deal with each case specifically.

COMPARISON OF EN 1179 AND ASTM B6

Color Code	EN 1179 Classification	ASTM B6 Classification	Differences
White	Z1	LME Grade	None
Yellow	Z2	Special High-Grade	ASTM B6 max Lead: 0.003% EN 1179 max Lead: 0.005% EN 1179 has no limit on Aluminum
Green	Z3	High Grade	ASTM B6 max Cadmium: 0.01% EN 1179 max Cadmium: 0.005% EN 1179 has no limit on Aluminum
Blue	Z4	Intermediate Grade	ASTM B6 max Cadmium: 0.01% EN 1179 max Cadmium: 0.005% EN 1179 has no limit on Aluminum EN 1179 has no limit on Copper
Black	Z5	Prime Western Grade	ASTM B6 max Cadmium: 0.20% EN 1179 max Cadmium: 0.005% EN 1179 has no limit on Aluminum EN 1179 has no limit on Copper

TABLE 1 OF ASTM B6- CHEMICAL REQUIREMENTS

	Composition %
Grade	Color Code	Lead	Iron Max	Cadmium Max	Aluminum Max	Copper Max	Tin Max	Total Non-Zinc Max	Zinc, min by difference
LME Grade	White	0.003 max	0.002	0.003	0.001	0.001	0.001	0.005	99.995
Special High Grade	Yellow	0.003 max	0.003	0.003	0.002	0.002	0.001	0.01	99.990
High Grade	Green	0.03 max	0.02	0.01	0.01	0.002	0.001	0.02	99.95
Intermediate Grade	Blue	0.45 max	0.05	0.01	0.01	0.20	-	0.5	99.5
Prime Western Grade	Black	0.05 - 1.4	0.05	0.01	0.01	0.10	-	1.5	98.5

TABLE 1 OF EN 1179- CHEMICAL COMPOSITION OF PRIMARY ZINC

Grade classifi-cation	Color Code	Composition in % (mass fraction)
		Nominal Zinc Content	1	2	3	4	5	6	Total of elements in columns 1 to 6
			Pb max	Cd max	Fe max	Sn max	Cu max	Al max
Z1	White	99,995	0,003	0,003	0,002	0,001	0,001	0,001	0,005
Z2	Yellow	99,99	0,005	0,003	0,003	0,001	0,002	-	0,01
Z3	Green	99,95	0,03	0,005	0,02	0,001	0,002	-	0,05
Z4	Blue	99,5	0,45	0,005	0,05	-	-	-	0,5
Z5	Black	98,5	1,4	0,005	0,05	-	-	-	1,5