Phthalates in school supplies

5. What daily exposure levels to phthalates are considered safe?

Current understanding about the effects of exposure to a specific phthalate on human health is mainly based on findings from animal studies.

Above certain exposure levels different phthalates do cause harmful effects in animals. The harmful effects of a given phthalate that occur at the lowest levels of exposure are referred to as critical toxic effects.

Phthalates banned across the EU in all toys and childcare articles, and in cosmetics:

• DEHP (Di-(2-ethylhexyl) phthalate)
  The critical toxic effects of DEHP that appear at the lowest exposure level relate to reproduction. The no-observed adverse effect level (NOAEL) for reproductive and developmental effects is 4.8 mg/kg body weight per day body weight per day, and the tolerable daily intake (TDI) is 0.05 mg/kg body weight per day. Exposure to DEHP at the doses observed in humans does not represent a relevant risk for the development of cancer.
• BBP (Benzylbutyl phthalate)
  Studies on rats show a NOAEL for BBP of 100 mg/kg body weight per day for effects on reproductive organs. The NOAEL for developmental effects was 20 mg/kg body weight per day in a study and of 50 mg/kg body weight per day in another report. The TDI for BBP is 0.5 mg/kg body weight per day.
• DBP, sometimes written DNBP (Di-n-butyl phthalate)
  The toxicity of DBP targets the male reproductive system, with a NOAEL of 50 mg/kg body weight per day. A study on rats showed that feeding DBP to mothers in late pregnancy and during lactation affected the development of both male and female offspring. A NOAEL could not be established, but a TDI of 0.01 mg/kg body weight per day was derived using a high safety factor.

Phthalates banned in toys and childcare products that children could put into their mouths:

• DINP (Di-isononyl phthalate)
  DINP is a mixture of compounds with different chemical structures, but with similar properties. The main toxicological effects for DINP are changes in the liver, with a NOAEL of 15 mg/kg body weight per day, and a TDI of 0.15 mg/kg body weight per day. For adverse effects on reproduction, the NOAEL varies between 500 mg/kg body weight per day and 622 mg/kg body weight per day.
• DIDP (Di-isodecyl phthalate)
  DIDP and DINP are very similar, both in structure and properties. There is no indication that DIDP has any effect on the reproductive organs. Overall, a NOAEL for effects on the liver of 15 mg/kg body weight per day derived from a study on dogs can be considered for humans. Although no TDI is available, exposures below 0.15 mg/kg body weight per day are of low concern as this figure is 100 smaller than the NOAEL, which is a good margin of safety.
• DNOP (Di-n-octylphthalate)
  The results of toxicological studies show that DNOP is very unlikely to cause adverse reproductive and developmental effects. However, it can have an effect on the activity of the liver and damage the thyroid. No TDI is available for DNOP.

Not yet evaluated in an EU Risk Assessment Report:

• DIBP (Di-isobutyl phthalate)
  The effects of DIBP on development and reproduction are similar to those observed for DBP and DEHP. However, there is no information on how these effects depend on the dose given. Further studies are thus needed to characterise the effects of DIBP on reproduction and derive a NOAEL. A TDI has not been defined.

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Overview table of critical toxic effects and Tolerable Daily Intakes (TDI)

Phthalate	Critical Toxic Effect on	Tolerable daily intake (in mg per kg body weight per day)	EU ban
DEHP	Reproduction	0.05	Banned in all toys and childcare articles, and in cosmetics
BBP	Reproduction and development	0.5
DBP		0.01
DINP	Liver	0.15	Banned in toys and childcare products that children could put into their mouths
DIDP
DNOP	Liver and thyroid	No TDI available
DIBP	Reproduction and development		-