Table 2.

Overview of existing heavy metals standards that are referenced in this paper, adapted from Banach et al.²⁶.

Metal	1a. Seaweed-specific		1b. Proposition 65 Safe Harbor Levels
	Feeda	Food supplementsb	MADLc	NSRLc
Total arsenic (AsT)	40 mg/kg	No standard	None provided	None provided
Inorganic arsenic (iAs)	2 mg/kg	No standard	None provided	10 μg/day
Cadmium (Cd)	1 mg/kg	3.0 mg/kg wet weight	4.1 μg/day	n/a for oral intake
Lead (Pb)	10 mg/kg	3.0 mg/kg wet weight	0.5 μg/dayd	15 μg/day
Mercury (Hg)	0.1 mg/kg	0.1 mg/kg wet weight	0.3 µg/day	None provided

^aDirective 2002/32/EC specifies this level relative to feed with a moisture content of 12%

^bRegulation (EC) No 1881/2006 on setting maximum levels for certain contaminants in foodstuffs and food supplements.

^cProposition 65 Safe Harbor Levels for maximum allowable dose level (MADL) and no significant risk level (NSRL) for oral intake⁴⁴.

^dIntake mechanism not specified.