# N,N-Dimethyl-p-toluidine: MAK Value Documentation – Translation of the German version from 2022

## TL;DR

This paper documents the health risks of N,N-dimethyl-p-toluidine and sets an occupational exposure limit based on its carcinogenic and mutagenic effects.

## Contribution

The paper provides a comprehensive toxicological evaluation and updates the MAK value for N,N-dimethyl-p-toluidine.

## Key findings

- N,N-dimethyl-p-toluidine causes liver tumors in mice and rats at specific doses.
- The compound induces DNA damage and is classified as a carcinogen and mutagen.
- Percutaneous absorption is expected to contribute to systemic toxicity.

## Abstract

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) has evaluated the occupational exposure limit value (maximum concentration at the workplace, MAK value) of N,N-dimethyl-p-toluidine [99-97-8] considering all toxicological end points. Relevant studies were identified from a literature search. N,N-Dimethyl-p-toluidine led to an increased incidence of liver adenomas and carcinomas in mice at 6 mg/kg body weight and day and in rats at 60 mg/kg body weight and day in a chronic gavage study. Additional tumours were observed in male rats in the transitional epithelium of the nose and in female rats in the lungs and the forestomach. On the basis of these effects, N,N-dimethyl-p-toluidine has been classified in Carcinogen Category 2. N,N-Dimethyl-p-toluidine induces mutagenic, aneugenic and clastogenic effects in vitro. In vivo, N,N-dimethyl-p-toluidine was found to cause DNA damage in the livers of rats and mice. As studies for germ cell mutagenicity are not available, N,N-dimethyl-p-toluidine has been classified in Germ Cell Mutagenicity Category 3 B. According to skin absorption models, percutaneous absorption is expected to contribute significantly to systemic toxicity. Therefore, N,N-dimethyl-p-toluidine has been designated with “H”. A sensitizing potential is not expected from the data available.