Chloromethane

City of Rialto

Chloromethane is an industrial solvent, aerosol propellant and a refrigerant. It also forms as a byproduct of water disinfection. The EPA classifies chloromethane as possibly carcinogenic to humans.

MORE ABOUT THIS CONTAMINANT

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2014	ND	17	ND
2015	ND	2	ND
2016	ND	9	ND
2017	ND	2	ND
2018	N/A	0	N/A
2019	ND	4	ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 2.69 ppb

The EWG Health Guideline of 2.69 ppb for chloromethane was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against cancer.

ppb = parts per billion

All test results

Date	Lab ID	Result
2014-03-04	B4C0466-01	ND
2014-03-04	B4C0466-03	ND
2014-03-04	B4C0466-05	ND
2014-03-05	B4C0599-01	ND
2014-03-10	B4C1035-01	ND
2014-03-13	B4C1366-01	ND
2014-04-15	B4D1509-01	ND
2014-06-10	B4F0945-01	ND
2014-06-10	B4F0950-01	ND
2014-09-10	B4I1057-01	ND
2014-09-10	B4I1053-01	ND
2014-09-11	B4I1249-05	ND
2014-09-11	B4I1249-03	ND
2014-09-11	B4I1249-07	ND
2014-09-11	B4I1249-01	ND
2014-09-18	B4I1960-01	ND
2014-12-11	B4L1410-03	ND
2015-11-30	4790-045-1020	ND
2015-12-18	4790-045-0915	ND
2016-03-11	4790-046-1120	ND
2016-03-11	4790-001-1220	ND
2016-03-11	4790-017-0850	ND
2016-03-11	4790-018-1045	ND
2016-03-11	4790-019-1440	ND
2016-03-11	4790-045-1145	ND
2016-04-30	4790-004-1145	ND
2016-06-02	4790-045-1240	ND
2016-09-01	4790-045-0945	ND
2017-07-10	5806-046-1045	ND
2017-09-25	4790-045-1200	ND
2019-03-20	4790-019-1250	ND
2019-03-20	4790-018-1215	ND
2019-03-20	4790-017-1330	ND
2019-04-17	4790-004-1315	ND