2.5. Heavy Metals

Heavy metals which are toxic to humans, can be found in various agricultural raw materials, including cocoa. 

Some food safety authorities have set maximum limits for certain metals in foods based on their assessments of the tolerable weekly intake (TWI) (“safe level”), and mean dietary exposure of groups and sub- groups of their populations, to protect the health of consumers. 

EU maximum limits for environmental contaminants are reviewed on a regular basis, and the introduction of maximum limits for nickel in cocoa products is currently under consideration based on an updated EFSA Scientific Opinion (EFSA Contam panel, 2020).

All maximum limits are subject to future revision to take account of the latest evidence and data, but there are currently no maximum regulatory limits under European legislation for arsenic or mercury in cocoa products.

Maximum limits are in force for heavy metals in cocoa products in some countries and states, for example for cadmium (Cd) and lead (Pb) under Prop65 in California.
 

2.5.1. Cadmium:

Cadmium (Cd) can accumulate in human tissue over time and can cause kidney and bone damage as well as being a carcinogen.

Maximum limits for Cd in cocoa products have been in force in Europe since 2019 under EU Regulation 2023/915 (see Table 1). 

The Codex Alimentarius Commission (CAC) set up a working group in 2014 to develop harmonised maximum levels which will protect consumer health and facilitate international trade. After several years of extensive discussions, the levels adopted by Codex for Cd are 0.3mg/kg for the category of chocolate containing up to 30 percent cocoa total solids on a dry matter basis and 0.7mg/kg for the 30 to 50 percent category, whilst noting the reservations of some delegations including that from the EU. 

A level of 2.0 mg/kg cocoa powder (100% total cocoa solids on a dry matter basis) is still in the process of being adopted by Codex, though with reservations expressed by some delegations, having reached Stage 5 of the 8 stage process.

A Code of Practice for the Prevention and Reduction of Cadmium in Cocoa Beans was adopted by Codex in 2022 (CAC CXC81, 2022). 

The Cd problem relates to beans from certain regions of some producing countries, particularly in the Latin America and Caribbean area. 

Although high levels in the beans are generally associated with naturally high levels of Cd in the soil, levels are known to be affected by a number of factors including the physical and chemical nature of the soil, the variety of cacao and anthropogenic factors including the use of contaminated fertilisers, composts and irrigation water. See Section 3 for suggestions on ways to mitigate against Cd uptake.
 

Table 1.

EU Maximum Limits for Cadmium in Cocoa Products applicable from 1st January 2019 (Commission Regulation (EU) 2023/915 replacing Commission Regulation (EU) No 488/2014)).

2.5.2. Lead:

This heavy metal can accumulate in human tissue over time and can cause damage to the kidney and the cardiovascular system. 

However, food safety authorities are particularly concerned about lead intake by pregnant women, infants and children since lead has a serious effect on neurodevelopment. EFSA updated its scientific opinion on lead in food in 2013 ((EFSA CONTAM, 2010 rev 2013) following an assessment of dietary exposure for the European population in 2012 (EFSA, 2012). A maximum lead level of 0.10mg / kg has been set for oils and fats (this category includes cocoa butter) (EU Regulation 2023/915). 

Lead levels in cocoa and chocolate products should continue to be carefully monitored and steps taken throughout the supply chain to minimise contamination.

Lead can occur naturally in the soil though, depending on soil factors such as pH and organic matter content, it is often insoluble and thus not taken up by the plant. 

However, lead can be released into the environment during forest fires, mining, smelting and petroleum extraction operations and when fossil fuels are burned (Baligar, Fageria, & Elrashidi, 1998). 

Contamination attributed to car exhaust fumes has considerably decreased since lead has been removed as an additive from petrol in most countries, though traffic fumes may still be a source of contamination and cocoa should not be dried or stored close to busy roads. 

Codex has published a code of practice for the prevention and reduction of lead contamination in foods (CAC CXC 56- 2004 rev 2021).

Click here for further sources of information.
 

2.5.3 Nickel

Recently maximum limits for Nickel have been introduced for some cocoa products, amongst other foods (EU 2024/1987) following the updated EFSA risk assessment of Nickel in food and water (EFSA Contam panel, 2020)

Table 2.

REGULATION (EU) 2024/1987 amending Regulation (EU) 2023/915 as regards the maximum levels for nickel in certain foodstuffs